Kilmer's genomic tests identified a rearrangement in the PALB2 gene.
|
|
Largely it's been a rearrangement of deck chairs on Google's video vessel.
|
|
But he underestimated how powerful the rearrangement of the present would be.
|
|
A second encryption method called transposition consists in the rearrangement of letters.
|
|
Cloud demonstrates a belief in the politics that lies in acts of rearrangement.
|
|
The civil war, which led to one such rearrangement, started the following month.
|
|
We haven't done the best job of adapting to that rearrangement of society so far.
|
|
Who will decide whether the policy is a fundamental change or simply an institutional rearrangement?
|
|
Noisey: What inspired you to go in the 1985 direction with the Justin Bieber rearrangement?
|
|
Yes. What specific 80s movie do you see the "What Do You Mean" rearrangement in?
|
|
Here's what you need to know: • The rearrangement of American alliances under President Trump continues apace.
|
|
Hierarchical forms of power and privilege in America would have undergone a significant measure of rearrangement.
|
|
Their rearrangement is timed to coincide with the anniversary of the song's March 7, 1983 release date.
|
|
Any growth-supporting measures, therefore, must come from new revenue sources and a rearrangement of national priorities.
|
|
"The unique feature is the rearrangement of the original 64 squares," Chappell wrote in Hyperchess's instruction manual.
|
|
Taking kambo leads to a massive rearrangement and overload of the nervous system; it changes our neurochemistry.
|
|
The place is undergoing a sort of rearrangement that is common in the transformation of any neighborhood.
|
|
There is a broad swath of the Radical thinking that was dedicated to the power of rearrangement.
|
|
Week 10 was the week of upsets in the NFL, causing a rearrangement of our NFL Power Rankings.
|
|
For organised criminals, Brexit is perhaps the most promising rearrangement of the European scene since the fall of communism.
|
|
Much of the genomic instability and rearrangement recorded by the twins study was probably the result of space radiation.
|
|
The production tells its tale clearly and efficiently, setting each scene with a deft rearrangement of picturesque panels and props.
|
|
When the dust settles on Mr. Trump's rearrangement of relations with Mexico, Mexico is unlikely to keep lending a hand.
|
|
The other fiscal change that I could see is an equally politically contentious rearrangement of national priorities within the federal budget.
|
|
The internal rearrangement of priorities for Apple is very much evident in the changes the company has made in recent years.
|
|
The bag also has weight sensors, which can help travelers avoid the embarrassing rearrangement of their bags at the check-in counter.
|
|
In Manhattan, this need for rearrangement has been exploited by developers who claim they require more floors for mechanicals than they do.
|
|
He internalized Balanchine's fast footwork, his precise musicality, the way that he could generate seemingly infinite shapes from the rearrangement of bodies onstage.
|
|
"A major factor in that shift has been a rearrangement in supply chains by Samsung Electronics and LG Electronics," Panjiva said in the report.
|
|
By some clever rearrangement in markets around the US, airwaves set aside for TV broadcasts will be repurposed for wireless, hopefully offsetting that problem.
|
|
A custom-built display shelf also runs the length of the storage space, allowing easy rearrangement and consideration of drawings without risking damage in transport.
|
|
In the rearrangement of relievers that Girardi said would most likely take effect as soon as the appropriate game situation presented itself, it's another story altogether.
|
|
So at the end of the day, this is more of a tax rearrangement than a tax cut outright," Bianco said Tuesday on CNBC's "Closing Bell.
|
|
Both candidates were vowing to lead nothing less than a rearrangement of military priorities, pledging to turn the war around with fresh thinking and more troops.
|
|
Later, I thought her rearrangement of my little paintings paralleled the structure of her "Field" paintings, which she made later that year and the next year.
|
|
Preliminary studies suggest that tumors with this genetic rearrangement could be susceptible to the drug Lynparza, but those effects haven't been definitively proven in large-scale studies.
|
|
The placement and rearrangement of bodies focuses the drama and heightens the character of the chorus, whose members grow from laughing at the Madwoman to pitying her.
|
|
" Beatrice "couldn't recognize a change inside herself, a minute yet radical sifting, a rearrangement at her very core, where a tiny fist of longing for a child grew.
|
|
" Miziolek announced yesterday that the art would go back up on view until May 6, at which point the museum's 20th- and 21st-century galleries will undergo "rearrangement.
|
|
And that the promise of restoring the hallowed norms Trump now shreds for fun is a workable antidote to the tribalism that would make such quick partisan rearrangement improbable.
|
|
That's one of the primary joys of "Confusions," watching chameleon performers change identities with wigs and accents, while locations are transformed by the rearrangement of simple pieces of furniture.
|
|
The iterative rearrangement of painting's fundamentals in the search of ultimate completion is the most salient feature of Cheim & Read's current exhibition of works by Serge Poliakoff (1900–69).
|
|
It's possible that this process of breakup and rearrangement has happened throughout the lifetime of comet 67P, and that it may be a common feature of "bilobed" comets in general.
|
|
Isabella Gardner (1840-1924), who positioned every item in her house-museum just so, and forbade rearrangement, placed the painting deliberately to give it plenty of gilt-enhancing natural light.
|
|
Under the rearrangement the agency would disband the National Center for Environmental Research, a federal environmental office that works to test the effects of chemical exposure on adults and children.
|
|
There are serious concerns about using CRISPR to edit genes in adults with inheritable diseases, including off-target editing that can cause cancers and or large deletions and rearrangement of DNA.
|
|
Bianco Research founder Jim Bianco thinks the market would likely do just fine without the GOP's tax plan, which he believes would result in more of a "rearrangement" than a cut.
|
|
The rearrangement of the widely followed blue-chip index of 30 companies would happen on April 2 before the U.S. stock market opens, S&P Dow Jones Indices said in a statement.
|
|
The sudden disappearance of a variety of widely available public forums for the alt-right has created a sudden rearrangement of its media ecosystem into a chaotic, yet-shapeless blob of vitriol.
|
|
Letter reordering, by definition, makes up about half of the entries in one of these; the first pass I make through clues always means scanning for words that look ripe for rearrangement.
|
|
S&P Dow Jones Indices and MSCI have maintained the widely used business classification system since 5003, and the rearrangement is meant to reflect how the tech, media and consumer industries have evolved.
|
|
Don McGahn (May): The White House Counsel, who worked on the bungled travel ban rollout and was warned Flynn could cause trouble for Trump, could be included in the rearrangement of Trump advisors.
|
|
Though many assume the only thing victims want is jail time for the perpetrator, many students' most urgent needs are emergency health care, an academic accommodation or housing rearrangement, and mental health support.
|
|
Interior Minister Wolfgang Sobotka has said the government supports a planned "thorough architectural rearrangement" of the house Hitler was born in near the border with Germany in 1889, which could include demolishing the building.
|
|
The new setup feels like a cross between a text message thread and a traditional command line interface, and Leavitt's team generally prefers the rearrangement over how the app is organized on the iPad.
|
|
While gaining like everyone from a better health market, the big losers in the rearrangement of subsidies will be wealthier people, including business executives and well-paid labor leaders who have traditionally opposed it.
|
|
If they get sufficiently close, their dark matter halos will start to pass through each other, and the rearrangement of the independently moving particles will give rise to dynamical friction, pulling the halos even closer.
|
|
The NBA off-season has been marked by a stunning, swift rearrangement of the championship contender map as players have asserted their talent off the court as strategic thinkers and masters of their own destiny.
|
|
Francine Prose New York City Do we really need to have a conversation about whether pastiche, parody, reframing, transposition, and creative rearrangement—basic concepts in twentieth- and twenty-first-century aesthetics—are acceptable in literature?
|
|
Finally, Biden was partially assisted by the dramatic rearrangement of the viable candidates after South Carolina when the moderates, Amy Klobuchar and Pete Buttigieg, dropped out while the left was divided by Warren remaining in the race.
|
|
The German-born Uffizi director began rehanging the museum's headliners in October 2016 — his predecessor Antonio Natali also made changes in the museum — with a rearrangement of the rooms for Botticelli and other late-15th-century artists.
|
|
The German-born Uffizi director began rehanging the museum's headliners in October 83 — his predecessor Antonio Natali also made changes in the museum — with a rearrangement of the rooms for Botticelli and other late-28th-century artists.
|
|
Direct chemical surgery is an appropriate analogy because base editors actually catalyze the rearrangement of atoms on the target DNA base to transform that DNA base from a C to something that looks like a T (for example).
|
|
Instead, he was the leader of a holding company called Alphabet, a rearrangement of the company that left Page in charge, but gave a degree of autonomy to the leaders of its various divisions, who now assumed CEO titles.
|
|
The chief authors were the Mariinsky's choreographers Marius Petipa and Lev Ivanov and the composer Riccardo Drigo, whose rearrangement of the score (possibly following some of Tchaikovsky's stated intentions) was radical — extensively reordering numbers, cutting and even adding items — and beautiful.
|
|
A 2016 study by Stefan Mundlos at the Max Planck Institute for Molecular Genetics in Berlin and his colleagues showed that a rearrangement of DNA in a noncoding region of the genome caused limb malformations during development by changing chromatin folding.
|
|
Of course they believed private valuations had become preposterous; of course the run in private tech stocks couldn't possibly last; and of course, many start-ups, especially those of the "Uber for garden-gnome rearrangement" variety, are in fact largely worthless.
|
|
Even if by some small miracle the exit is even a slight success, it will still leave a lot of rearrangement for the EU.This includes security policy — the UK has a powerful global army and it also has nuclear weapons.
|
|
Keith Urban found MacKenzie's rearrangement of Cheap Trick's "I Want You To Want Me" middling and maudlin and would've preferred it completely stripped down, while Harry Connick Jr. thought the song needed its original double-time beat to energize it.
|
|
Now a committee of experts including historians, officials and the head of Austria's main Jewish organization has recommended that a "thorough architectural rearrangement" be carried out, and Interior Minister Wolfgang Sobotka intends to follow their suggestion, a spokesman for the minister said.
|
|
The marginalisation of the 81-year-old Mr Berlusconi highlighted another characteristic of the biggest rearrangement of the political landscape since he stormed onto the scene in 1994: like Brexit and the election of Donald Trump, it was a thundering rejection of the establishment.
|
|
The experiment showed that meiosis, the special process of cell division and genetic rearrangement required to form germ cells (sperm and eggs), can be achieved in the lab by treating stem cells with a cocktail of chemicals and hormones in the presence of testicular tissue.
|
|
"The challenge is that Trump's trade policy has proven so erratic that you cannot relieve the sense of uncertainty," as firms adjust to what may be a years-long rearrangement of global supply chains and cost structures, said Tim Duy, an economics professor at the University of Oregon.
|
|
Wasserman Projects spared no effort in the rearrangement of their typically wide-open floor plan, creating darkened zones for intimate encounters for some of Shalev-Gerz's video works, and mirrored, museum-like display kiosks for delicate glass sculpture pieces, all of which strive to reinforce Wasserman's vision for a Kunsthalle effect.
|
|
"Dodik is arguably the most outspoken proponent of wholesale territorial rearrangement in the region, so he will likely use his post to continue to undermine the existing regional status quo, to invite greater Russian influence, and likewise to trump up Serb nationalist grievances both in Bosnia and across the Balkans," Mujanovic told BuzzFeed News.
|
|
But perhaps it's true to life: what we leave behind in the natural world is ultimately a fairly orderly record of our movement through time and space, whereas our memories and other thought processes about our place in nature though delicately balanced against one another, are far more haphazard, and in a constant state of rearrangement.
|
|
I happened to attend a press screening on the day preceding the one year anniversary of my own mother's death; perhaps unsurprisingly, I melted into tears as Blunt delivered a compassionate and graceful performance of "The Place Where the Lost Things Go," wherein she reassures Anabel, John, and Georgie that death never means annihilation, but rather a cosmic rearrangement.
|
|
If you consider this detail — wedged into an otherwise painstakingly accurate reality — you can start to see the contours of the ascendant televised version of New York, not at all limited to "High Maintenance," in which the collisions generated by the city's constant rearrangement of humanity bring us all, in the end, to greater mutual understanding.
|
|
In a statement, KFC said the ad was a "tongue-in-cheek rearrangement of our brand name intended to indicate our first thought when we realized the impact of our closed restaurants on customers in the U.K." The ad was in keeping with the public-relations approach that had been employed ever since the scale of the supply-chain snafu made itself apparent.
|
|
Another variation of the Cope rearrangement is the heteroatom Cope reactions such as the aza-Cope rearrangements. Another widely studied [3,3] sigmatropic rearrangement is the Claisen rearrangement. Also see the divinylcyclopropane-cycloheptadiene rearrangement.
|
|
These data are summarized in :950px Plausible mechanisms of the Wagner–Meerwein rearrangement of diepoxyisoindoles: 1000px The related Nametkin rearrangement named after Sergey Namyotkin involves the rearrangement of methyl groups in certain terpenes. In some cases the reaction type is also called a retropinacol rearrangement (see Pinacol rearrangement).
|
|
The Overman rearrangement (named after Larry Overman) is a Claisen rearrangement of allylic trichloroacetimidates to allylic trichloroacetamides. The Overman rearrangement The Overman rearrangement is applicable to the synthesis of vicinol diamino compounds from 1,2-vicinal allylic diols.
|
|
The first reported Claisen rearrangement is the [3,3]-sigmatropic rearrangement of an allyl phenyl ether to intermediate 1, which quickly tautomerizes to an ortho- substituted phenol. The Claisen rearrangement Meta-substitution affects the regioselectivity of this rearrangement. For example, electron withdrawing groups (such as bromide) at the meta-position direct the rearrangement to the ortho-position (71% ortho product), while electron donating groups (such as methoxy), direct rearrangement to the para-position (69% para product). Additionally, presence of ortho substituents exclusively leads to para- substituted rearrangement products (tandem Claisen and Cope rearrangement).
|
|
The Hayashi rearrangement can be considered as the cationic counterpart of Smiles rearrangement.
|
|
In these materials, the rearrangement is thought to have important implications for the chemical, electrical, and mechanical properties. The rearrangement is an example of a pyracyclene rearrangement.
|
|
The Beckmann rearrangement, named after the German chemist Ernst Otto Beckmann (1853–1923), is a rearrangement of an oxime functional group to substituted amides. The rearrangement has also been successful performed on haloimines and nitrones. Cyclic oximes and haloimines yield lactams. The Beckmann rearrangement is often catalyzed by acid, however other reagents have been known to promote the rearrangement.
|
|
The Claisen rearrangement is a powerful carbon–carbon bond-forming chemical reaction discovered by Rainer Ludwig Claisen. The heating of an allyl vinyl ether will initiate a [3,3]-sigmatropic rearrangement to give a γ,δ-unsaturated carbonyl. The Claisen rearrangement Discovered in 1912, the Claisen rearrangement is the first recorded example of a [3,3]-sigmatropic rearrangement. Many reviews have been written.
|
|
Reactions of type 4 are also called acyloin rearrangements. While similar to the pinacol rearrangement, the semipinacol rearrangement differs from the pinacol rearrangement in that the cation is not formed from a vicinal 1,2-diol. With diazoalcohols the reaction is known as the Tiffeneau–Demjanov rearrangement.
|
|
Due to the mild heating conditions of the reaction carried out, unlike the more stringent ones for a purely hydrocarbon Cope rearrangement, this heteroatomic Cope rearrangement introduced the hypothesis that having a positive charge on a nitrogen in the cope rearrangement significantly reduces the activation barrier for the rearrangement.
|
|
The Ireland–Claisen rearrangement is a type of Claisen rearrangement. The mechanism is therefore a concerted [3,3]-sigmatropic rearrangement which according to the Woodward–Hoffmann rules show a concerted, suprafacial, pericyclic reaction pathway.
|
|
The Hofmann–Martius rearrangement in organic chemistry is a rearrangement reaction converting an N-alkylated aniline to the corresponding ortho and / or para aryl-alkylated aniline. The reaction requires heat, and the catalyst is an acid like hydrochloric acid. :The Hofmann–Martius rearrangement When the catalyst is a metal halide the reaction is also called the Reilly–Hickinbottom rearrangement. The reaction is also known to work for aryl ethers and two conceptually related reactions are the Fries rearrangement and the Fischer–Hepp rearrangement.
|
|
The Wallach rearrangement is an organic reaction converting an aromatic azoxy compound with sulfuric acid or other strong acids to an azo compound with one arene ring substituted by a hydroxyl group in the aromatic para position.Catalysis in strongly acidic media and the Wallach rearrangement Erwin Buncel Acc. Chem. Res.; 1975; 8(4) pp 132 – 139; Wallach-Umlagerung-general reaction scheme Conceptually related reactions are the Fries rearrangement, the Fischer–Hepp rearrangement, the Bamberger rearrangement, the benzidine rearrangement and the Hofmann–Martius rearrangement. In the first part of the reaction, two equivalents of acid tease the oxygen atom away from the azoxy group.
|
|
A specific example of this is the Baker–Venkataraman rearrangement, in which an aromatic ortho- acyloxy ketone undergoes an intramolecular nucleophilic acyl substitution and subsequent rearrangement to form an aromatic β-diketone.Kürti and Czakó 2005, p. 30. The Chan rearrangement is another example of a rearrangement resulting from an intramolecular nucleophilic acyl substitution reaction.
|
|
The vinylogous Wolff rearrangement consists of a β,γ-unsaturated diazo ketone undergoing a Wolff rearrangement, and a formal 1,3-shift of the CH2CO2R group. The vinylogous Wolff rearrangement yields a γ,δ-unsaturated carboxylic acid derivative, which is the same retron as for the Claisen rearrangement. The variant was discovered when it was noticed that thermolysis of 1-diazo-3,3,3-triarylpropan-2-ones gave unexpected isomeric products. First example of vinylogous Wolff rearrangement.
|
|
In catalysis silver is active as silver oxide in the Wolff rearrangement. Silver nitrate is used to separate out alkenes as the η2-alkene complex. Silver is also present in other carbon-carbon bond skeletal rearrangements such as the quadricyclane to norbornadiene rearrangement, the cubane to cuneane rearrangement and the rearrangement of the cyclobutadiene dimer to cyclooctatetraene.
|
|
The Baker–Venkataraman rearrangement is the chemical reaction of 2-acetoxyacetophenones with base to form 1,3-diketones. The Baker-Venkataraman rearrangement This rearrangement reaction proceeds via enolate formation followed by acyl transfer. It is named after the scientists Wilson Baker and K. Venkataraman. The Baker–Venkataraman rearrangement is often used in the synthesis of chromones and flavones.
|
|
The corresponding reaction involving an ether is the 1,2-Wittig rearrangement. The reaction course in this rearrangement is different because ether cleavage with carbanion formation is unfavorable. The Pummerer rearrangement in one of its reaction step contains a sulfur variation.
|
|
The rearrangement of aldoximes occurs with stereospecificity in the gas phase and without stereospecificity in the solution phase. A few methodologies allow for the rearrangement of aldoximes to primary amides, but fragmentation commonly competes in these systems. Nitrone rearrangement also occurs without stereospecificity; the regioisomer formed has the amide nitrogen substituted with the group possessing the greatest migratory aptitude. The Beckmann Rearrangement The archetypal Beckmann rearrangement is the conversion of cyclohexanone to caprolactam via the oxime.
|
|
The Cope rearrangement of 3-methyl-hexa-1,5-diene The Cope rearrangement causes the fluxional states of the molecules in the bullvalene family.
|
|
Stieglitz Rearrangement hydroxylamines In general, the term "Stieglitz rearrangement" is used to describe a wide variety of rearrangement reactions of amines to imines. Although, it is generally associated with the rearrangement of triaryl hydroxylamines, that are well-reported in the academic literature, Stieglitz rearrangements can also occur on alkylated amine derivatives, haloamines and azides as well as other activated amine derivatives.
|
|
Upon creation of appropriately substituted enamines, intense heating afforded an almost complete rearrangement to the imine product. However, this rearrangement pathway has limited utility.
|
|
Allelic exclusion has been observed most often in genes for cell surface receptors and has been extensively studied in immune cells such as B lymphocytes. In B lymphocytes, successful heavy chain gene rearrangement of the genetic material from one chromosome results in the shutting down of rearrangement of genetic material from the second chromosome. If no successful rearrangement occurs, rearrangement of genetic material on the second chromosome takes place. If no successful rearrangement occurs on either chromosome, the cell dies.
|
|
In the anionic Fries rearrangement ortho-metalation of aryl esters, carbamates and carbonates with a strong base results in a rearrangement to give ortho-carbonyl species.
|
|
True sigmatropic reactions are usually uncatalyzed, although Lewis acid catalysis is possible. Sigmatropic reactions often have transition-metal catalysts that form intermediates in analogous reactions. The most well-known of the sigmatropic rearrangements are the [3,3] Cope rearrangement, Claisen rearrangement, Carroll rearrangement, and the Fischer indole synthesis.
|
|
Dienone-phenol rearrangement of 4,4-disubstituted cyclohexadienone into 3,4‐disubstituted phenol The dienone-phenol rearrangement is a reaction in organic chemistry first reported in 1921 by Auwers and Ziegler. A common example of dienone-phenol rearrangement is 4,4-disubstituted cyclohexadienone converting into a stable 3,4-disubstituted phenol in presence of acid. A similar rearrangement is possible with 2,2-disubstituted cyclohexadienone to its corresponding disubstituted phenol. Usually this type rearrangement is a spontaneous unless the presence of a dichloromethyl group at 3rd position or 4th position is blocked with any non hydrogen groups.
|
|
The Carroll rearrangement is a rearrangement reaction in organic chemistry and involves the transformation of a β-keto allyl ester into a α-allyl-β-ketocarboxylic acid.Carrol, M. F. Journal of the Chemical Society 1940, 704–706. . This organic reaction is accompanied by decarboxylation and the final product is a γ,δ-allylketone. The Carroll rearrangement is an adaptation of the Claisen rearrangement and effectively a decarboxylative allylation.
|
|
The Cope rearrangement is an extensively studied organic reaction involving the [3,3] sigmatropic rearrangement of 1,5-dienes.Cope, A. C.; et al. J. Am. Chem. Soc. 1940, 62, 441.
|
|
The Cope rearrangement is an extensively studied organic reaction involving the [3,3]-sigmatropic rearrangement of 1,5-dienes.Arthur C. Cope; et al.; J. Am. Chem. Soc. 1940, 62, 441.
|
|
The Jacobsen rearrangement is a chemical reaction, commonly described as the migration of an alkyl group in a sulfonic acid derived from a polyalkyl- or polyhalobenzene: Jacobsen rearrangement The exact reaction mechanism is not completely clear, but evidence indicates that the rearrangement occurs intermolecularly and that the migrating group is transferred to a polyalkylbenzene, not to the sulfonic acid (sulfonation only takes place after migration). The intermolecular mechanism is partially illustrated by the side products found in the following example: Jacobsen rearrangement Furthermore, the reaction is limited to benzene rings with at least four substituents (alkyl and/or halogen groups). The sulfo group is easily removed, so the Jacobsen rearrangement can also be considered as a rearrangement of polyalkylbenzenes. It was Herzig who described this type of rearrangement for the first time in 1881 using polyhalogenated benzenesulfonic acids, but the reaction took the name of the German chemist Oscar Jacobsen, who described the rearrangement of polyalkylbenzene derivatives in 1886.
|
|
Many ylides react in sigmatropic reactions. The Sommelet-Hauser rearrangement is an example of a [2,3]-sigmatropic reaction. The Stevens rearrangement is a [1,2]-rearrangement. A -sigmatropic reaction has been observed in certain phosphonium ylides(i) Reaction of allyl alcohol with 2-chloro-5,5-dimethyl-1,3,2-dioxaphosphorinane forms a phosphite ester.
|
|
The Overman rearrangement may also be used for asymmetric synthesis.Anderson, C. E.; Overman, L. E. J. Am. Chem. Soc. 2003, 125, 12412–12413. ()Asymmetric Overman Rearrangement Organic Syntheses, Vol.
|
|
Rearrangement reactions are fragmentation reactions that form new bonds producing an intermediate structure before cleavage. One of the most studied rearrangement reaction is the McLafferty rearrangement / γ-hydrogen rearrangement. This occurs in the radical cations with unsaturated functional groups, like ketones, aldehydes, carboxylic acids, esters, amides, olefins, phenylalkanes. During this reaction, γ-hydrogen will transfer to the functional group at first and then subsequent α, β-bond cleavage of the intermediate will take place.
|
|
The Neber rearrangement is an organic reaction in which a ketoxime is converted into an alpha-aminoketone via a rearrangement reaction. :Neber rearrangement The oxime is first converted to an O-sulfonate, for example a tosylate by reaction with tosyl chloride. Added base forms a carbanion which displaces the tosylate group in a nucleophilic displacement to an azirine and added water subsequently hydrolyses it to the aminoketone. The Beckmann rearrangement is a side reaction.
|
|
The 1,2-rearrangement belongs to a broad class of chemical reactions called rearrangement reactions. A rearrangement involving a hydrogen atom is called a 1,2-hydride shift. If the substituent being rearranged is an alkyl group, it is named according to the alkyl group's anion: i.e. 1,2-methanide shift, 1,2-ethanide shift, etc.
|
|
The Stieglitz rearrangement is a rearrangement reaction in organic chemistry which is named after the American chemist Julius Stieglitz (1867 – 1937) and was first investigated by him and Paul Nicholas Leech in 1913. It describes the 1,2-rearrangement of trityl amine derivatives to triaryl imines. It is comparable to a Beckmann rearrangement which also involves a substitution at a nitrogen atom through a carbon to nitrogen shift. As an example, triaryl hydroxylamines can undergo a Stieglitz rearrangement by dehydration and the shift of a phenyl group after activation with phosphorus pentachloride to yield the respective triaryl imine, a Schiff base.
|
|
Mechanism of a Beckmann rearrangement The Stieglitz rearrangement's reaction mechanism and the products and starting materials involved make it closely related to the Beckmann rearrangement, which can be used for the synthesis of carboxamides. Both rearrangement reactions involve a carbon to nitrogen shift, usually after electrophilic activation of the leaving group on the nitrogen atom. The main difference in the starting materials, however, is their saturation degree. While a Stieglitz rearrangement takes place on saturated amine derivatives with a σ-single bond, the typical starting material for a Beckmann rearrangement is an oxime (a hydroxylimine) with a C=N-double bond.
|
|
The vinylcyclopropane rearrangement or vinylcyclopropane-cyclopentene rearrangement is a ring expansion reaction, converting a vinyl-substituted cyclopropane ring into a cyclopentene ring. Vinylcyclopropane Rearrangement Intense experimental as well as computational investigations have revealed that mechanistically, the vinylcyclopropane rearrangement can be thought of as either a diradical-mediated two-step and/or orbital-symmetry-controlled pericyclic process. The amount by which each of the two mechanisms is operative is highly dependent on the substrate. Due to its ability to form cyclopentene rings the vinylcyclopropane rearrangement has served several times as a key reaction in complex natural product synthesis.
|
|
The Sommelet–Hauser rearrangement is a named reaction based on the work of Hauser and SommeletM. Sommelet, Compt. Rend. 205, 56 (1937). involving the rearrangement of certain benzyl quaternary ammonium salts.
|
|
The Tiffeneau-Demjanov rearrangement (after Marc Tiffeneau and Nikolai Demjanov) is a variation of the Demjanov rearrangement, which involves both a ring expansion and the production of a ketone by using sodium nitrite and hydrogen cation. Using the Tiffeneau-Demjanov reaction is often advantageous as, while there are rearrangements possible in the products, the reactant always undergoes ring enlargement. As in the Demjanov rearrangement, products illustrate regioselectivity in the reaction. Migratory aptitudes of functional groups dictate rearrangement products.
|
|
The Cope rearrangement of 3-methyl-1,5-hexadiene In a rearrangement reaction, the carbon skeleton of a molecule is rearranged to give a structural isomer of the original molecule. These include hydride shift reactions such as the Wagner-Meerwein rearrangement, where a hydrogen, alkyl or aryl group migrates from one carbon to a neighboring carbon. Most rearrangements are associated with the breaking and formation of new carbon- carbon bonds. Other examples are sigmatropic reaction such as the Cope rearrangement.
|
|
The Ireland–Claisen rearrangement is a chemical reaction of an allylic ester with strong base to give an γ,δ-unsaturated carboxylic acid. The Ireland- Claisen rearrangement Several reviews have been published.
|
|
Claisen, L.; Tietze, E.; Chemische Berichte 1926, 59, 2344. This rearrangement is a useful carbon-carbon bond-forming reaction. An example of Claisen rearrangement is the [3,3] rearrangement of an allyl vinyl ether, which upon heating yields a γ,δ-unsaturated carbonyl. The formation of a carbonyl group makes this reaction, unlike other sigmatropic rearrangements, inherently irreversible.
|
|
Alkenes can be synthesized from other alkenes via rearrangement reactions. Besides olefin metathesis (described above), many pericyclic reactions can be used such as the ene reaction and the Cope rearrangement. Cope rearrangement of divinylcyclobutane to cyclooctadiene In the Diels–Alder reaction, a cyclohexene derivative is prepared from a diene and a reactive or electron- deficient alkene.
|
|
The Overman rearrangement is a chemical reaction that can be described as a Claisen rearrangement of allylic alcohols to give allylic trichloroacetamides through an imidate intermediate.Organic Syntheses, Coll. Vol. 6, p.507; Vol.
|
|
Hence, it is often paired with a thermodynamic sink to bias a rearrangement product. In 1950, Horowitz and Geissman reported the first example of the 2-aza-Cope rearrangement, a surprising result in a failed attempt to synthesize an amino alcohol. This discovery identified the basic mechanism of the rearrangement, as the product was most likely produced through a nitrogen analog of the Cope rearrangement. Treatment of an allylbenzylamine (A) with formic acid and formaldehyde leads to an amino alcohol (B).
|
|
Apart from acid catalysis, the dienone-phenol rearrangement is also possible in presence of base. The dienone-phenol rearrangement found helpful in various synthetic protocols use towards the synthesis of steroids, anthracene, phenanthrene, etc.
|
|
In a Beckmann rearrangement, the acid catalyzed carbon to nitrogen migration takes place on the oxime to yield a nitrilium ion intermediate. In principle, the first step of a Stieglitz rearrangement proceeds in an analogous way. However, after the generation of the positively charged iminium ion through the π-interaction between the nitrogen lone pair and the electron deficient carbon in the Stieglitz rearrangement, the pathways diverge. In the Stieglitz rearrangement, a charge-neutral state of the molecule can be achieved by dissociation of a proton.
|
|
The rearrangement is commonly used to form strained bicyclic and ring-fused systems. There exist a handful of examples of ring contractions from cyclobutanones to cyclopropanes. The Wolff rearrangement is capable of contracting cyclohexanones to cyclopentanes, but is infrequently used to do so, because the Favorskii rearrangement accomplishes this transformation and the Wolff precursor is often more challenging to synthesize. However, an example of a cyclohexanone ring contraction using deformylative diazo transfer, followed by a Wolff rearrangement, is Keiichiro Fukumoto's synthesis of (±)-∆9(12)-capnellene.
|
|
Note that anion formation has been omitted. An alternative to the standard Favorskii rearrangement, is to perform what can be thought of as a negative pinacol rearrangement where an anionic group encourages a bond aligned with a leaving group to migrate and expel the leaving group, which has been used in several syntheses. It should also be noted that the so-called "quasi-Favorskii rearrangement" proceeds without an additional nucleophile to form the final contracted product. A general pinacol type rearrangement to an unequal 5,7 ring system.
|
|
The Mumm rearrangement is an organic reaction and a rearrangement reaction.Mumm, O. Ber. Dtsch. Chem. Ges. 1910, 43, 886-893Preparation of acyclic isoimides and their rearrangement rates to imides J. S. Paul Schwarz J. Org. Chem.; 1972; 37(18) pp 2906 - 2908; It describes a 1,3(O-N) acyl transfer of an acyl imidate or isoimide group to an imide.
|
|
1]hexane-6-carboxylic acid. Ring contraction of α-diazocamphor via Wolff-rearrangement, followed by hydration from more sterically accessible endo face. Ring contractions have been used extensively to build strained ring systems, as ring size does not impede the Wolff rearrangement, but often impedes other reactions. There are many examples where the Wolff rearrangement is used to contract cyclopentanone to cyclobutane.
|
|
58, p.4 (Article ) The Overman rearrangement was discovered in 1974 by Larry Overman. The Overman rearrangement The [3,3]-sigmatropic rearrangement is diastereoselective and requires heating or the use of Hg(II) or Pd(II) salts as catalysts. The resulting allylamine structures can be transformed into many chemically and biologically important natural and un-natural amino acids (like (1-adamantyl)glycine).
|
|
The facile nature of this rearrangement is attributed both to the fact that the cationic 2-aza-Cope is inherently thermoneutral, meaning there's no bias for the starting material or product, as well as to the presence of the charged heteroatom in the molecule, which lowers the activation barrier. Less common are the 1-aza-Cope rearrangement and the 3-aza-Cope rearrangement, which are the microscopic reverse of each other. The 1- and 3-aza-Cope rearrangements have high activation barriers and limited synthetic applicability, accounting for their relative obscurity. To maximize its synthetic utility, the cationic 2-aza-Cope rearrangement is normally paired with a thermodynamic bias toward one side of the rearrangement.
|
|
The Hayashi rearrangement is the chemical reaction of ortho-benzoylbenzoic acids catalyzed by sulfuric acid or phosphorus pentoxide. ; p. 1520 ; p. 1524 The Hayashi rearrangement This reaction proceeds through electrophilic acylium ion attack with a spiro intermediate.
|
|
Her doctoral research was on the rearrangement of quinone using sulfuric acid.
|
|
In one modification called the Truce–Smiles rearrangement the incoming nucleophile is sufficiently strong that the arene does not require this additional activation, for example when the nucleophile is an organolithium. This reaction is exemplified by the conversion of an aryl sulfone into a sulfinic acid by action of n-butyllithium: Truce–Smiles rearrangement This particular reaction requires the interaction of the alkyllithium group ortho to the sulfone group akin a directed ortho metalation. A conceptually related reaction is the Chapman rearrangement. A radical version of Smiles rearrangement is reported by Stephenson in 2015.
|
|
Like other ketogenic rearrangements, the α-ketol rearrangement involves the transformation of an alkoxide into a carbonyl group with concomitant movement of the bonding electrons of the migrating group towards an adjacent trigonal center. A distinctive feature of this particular rearrangement, however, is its reversibility—as a result, the more stable α-hydroxy carbonyl compound is favored. A general scheme for the rearrangement is shown below. (1)330px This rearrangement differs from similar isomerizations of carbohydrates, which involve the migration of hydrogen and proceed through discrete enediol intermediates.
|
|
Following this logic, much of the research on the 3-aza-Cope rearrangement has focused on charged zwitterionic versions of this reaction, as the charge distribution helps lower the activation barrier: in certain cases, the rearrangement can occur at temperatures as low as -20 °C. An excerpt of a 3-aza-Cope rearrangement in the total synthesis of deserpidine, by Mariano and coworkers. This step proceeded with 30-60% yield, dependent on allylic substituents (not shown). HIll and Gilman first reported a general uncharged 3-aza-Cope rearrangement in 1967.
|
|
The “1,5 ” hydrogen shift cause transfer of one γ- hydrogen to a radical site on a saturated heteroatom. The same requirements for McLafferty rearrangement apply to hydrogen rearrangement to a saturated heteroatom. Such rearrangement initiates charge-site reaction, resulting in the formation of an odd electron ion and a small neutral molecule ( water, or acid and so on). For alcohols, this heterolytic cleavage releases a water molecule.
|
|
The [2,3]-Wittig rearrangement is the transformation of an allylic ether into a homoallylic alcohol via a concerted, pericyclic process. Because the reaction is concerted, it exhibits a high degree of stereocontrol, and can be employed early in a synthetic route to establish stereochemistry. The Wittig rearrangement requires strongly basic conditions, however, as a carbanion intermediate is essential. [1,2]-Wittig rearrangement is a competitive process.
|
|
The amino alcohol converts to an imine under addition of acid (C), which undergoes the cationic 2-aza-Cope rearrangement (D). Water hydrolyses the iminium ion to an amine (E). Treating this starting material with only formaldehyde showed that alkylation of the amine group occurred after the cationic 2-aza-Cope rearrangement, a testament to the quick facility of the rearrangement. iminium ion formation by reductive amination.
|
|
Rearrangements, especially those that can participate in cascade reactions, such as the aza-Cope rearrangements, are of high practical as well as conceptual importance in organic chemistry, due to their ability to quickly build structural complexity out of simple starting materials. The aza-Cope rearrangements are examples of heteroatom versions of the Cope rearrangement, which is a [3,3]-sigmatropic rearrangement that shifts single and double bonds between two allylic components. In accordance with the Woodward-Hoffman rules, thermal aza-Cope rearrangements proceed suprafacially. Aza-Cope rearrangements are generally classified by the position of the nitrogen in the molecule (see figure): The 1,2, and 3 aza-Cope rearrangements The first example of an aza- Cope rearrangement was the ubiquitous cationic 2-aza-Cope Rearrangement, which takes place at temperatures 100-200 °C lower than the Cope rearrangement due to the facile nature of the rearrangement.
|
|
The Riesz rearrangement inequality can be used to prove the Pólya–Szegő inequality.
|
|
Auflage, Wiley-Interscience, Hoboken, NJ 2005, , S. 516. Imidates produced in this manner are formed as their hydrochloride salts, which are sometimes referred to as Pinner salts. Carboximidates are also formed as intermediates in the Mumm rearrangement and the Overman rearrangement.
|
|
The reaction now known as the Tiffeneau–Demjanov rearrangement (TDR) was discovered in two steps. The first step of occurred in 1901 when Russian chemist Nikolai Demyanov discovered that aminomethylcycloalkanes produce novel products upon treatment with nitrous acid. When this product was identified as the expanded alcohol in 1903, the Demjanov rearrangement was coined. The Demjanov rearrangement itself has since been successfully used in industry and synthetical organic chemistry.
|
|
The Mumm rearrangement The reaction is of relevance as part of the Ugi reaction.
|
|
Cuneane may be produced from cubane by a metal-ion-catalyzed σ-bond rearrangement.
|
|
These toxins ultimately lead to rearrangement of the cytoskeleton and entry of the bacteria.
|
|
The Favorskii rearrangement, named for the Russian chemist Alexei Yevgrafovich Favorskii, is most principally a rearrangement of cyclopropanones and α-halo ketones which leads to carboxylic acid derivatives. In the case of cyclic α-halo ketones, the Favorskii rearrangement constitutes a ring contraction. This rearrangement takes place in the presence of a base, sometimes hydroxide, to yield a carboxylic acid but most of the time either an alkoxide base or an amine to yield an ester or an amide, respectively. α,α’-Dihaloketones eliminate HX under the reaction conditions to give α,β-unsaturated carbonyl compounds.
|
|
The Stevens rearrangement in organic chemistry is an organic reaction converting quaternary ammonium salts and sulfonium salts to the corresponding amines or sulfides in presence of a strong base in a 1,2-rearrangement. Stevens rearrangement overview The reactants can be obtained by alkylation of the corresponding amines and sulfides. The substituent R next the amine methylene bridge is an electron-withdrawing group. The original 1928 publication by Thomas S. Stevens concerned the reaction of 1-phenyl-2-(N,N-dimethylamino)ethanone with benzyl bromide to the ammonium salt followed by the rearrangement reaction with sodium hydroxide in water to the rearranged amine.
|
|
The reaction mechanism of 4,4-disubstituted cyclohexadienones to 3,4-disubstituted phenol is illustrated here. Proposed Reaction mechanism of dienone-phenol Rearrangement The migration tendency for the two different groups (R) present at either 4,4 position or 2,2 position can be determined by comparing the relative stability of intermediate Carbocation formed in the time of rearrangement. In case of acid-promoted conditions, the migration tendencies few groups are like this COOEt > Phenyl (or alkyl); Phenyl > Methyl; vinyl > Methyl; Methyl > alkoxy and alkoxy > Phenyl. In some cases such as allyl and benzyl group, the actual rearrangement might undergo through the Cope Rearrangement.
|
|
For longer chain alcohols, a McLafferty type rearrangement can produce water and ethylene (M -46). McLafferty type rearrangement for long chain alcohols Cyclic alcohols tend to show stronger M+ peaks than linear chains. And they follow similar fragmentation pathways: Alpha cleavage and dehydration.
|
|
The Schiff Base then undergoes an isomerization by an Amadori rearrangement to form a ketosamine, or an Amadori rearrangement. The Amadori product can then undergo many further reactions to form various AGE products, which can also be further modified into different products.
|
|
The ketone then undergoes Wolff rearrangement to ketene 6. Ozonolysis forms the ketone 7, another diazotation yields the diazo ketone 8, which undergoes Wolff rearrangement again to the ketene 9. Reaction with dimethylamine affords the [2.2.2]propellane backbone with a dimethylamide substituent 10.
|
|
The superposed order allowed storeys without columns, but rearrangement of order styles was strictly forbidden.
|
|
His name is also associated with the chemical reaction known as the Wolff rearrangement (1912).
|
|
An unexpected/fortuitous rearrangement product in the synthesis of litracen is what lead to talopram.
|
|
This occurs through a Brook-rearrangement initiated by attack at the carbonyl group. A related reaction, involving initial attack at the silicon center, causes migration of one of the silicon groups to the carbonyl carbon, which initiates a Brook-Rearrangement. If the silicon group was chiral, the end product is a chiral silyl ether, as the migration occurs stereospecifically. Rearrangements analogous to the Brook Rearrangement are known for many other types of atoms.
|
|
The Ireland–Claisen rearrangement is the reaction of an allylic carboxylate with a strong base (such as lithium diisopropylamide) to give a γ,δ-unsaturated carboxylic acid. The rearrangement proceeds via silylketene acetal, which is formed by trapping the lithium enolate with chlorotrimethylsilane. Like the Bellus-Claisen (above), Ireland- Claisen rearrangement can take place at room temperature and above. The E- and Z-configured silylketene acetals lead to anti and syn rearranged products, respectively.
|
|
In organic chemistry, the oxy-Cope rearrangement is a chemical reaction. It involves reorganization of the skeleton of certain unsaturated alcohols. It is a variation of the Cope rearrangement in which 1,5-dien-3-ols are converted to unsaturated carbonyl compounds by a mechanism typical for such a [3,3]-sigmatropic rearrangement. The reaction is highly general: a wide variety of precursors undergo the reorganization predictably and with ease, rendering it a highly useful synthetic tool.
|
|
The benzilic acid rearrangement is formally the 1,2-rearrangement of 1,2-diketones to form α-hydroxy–carboxylic acids using a base. This reaction receives its name from the reaction of benzil with potassium hydroxide to form benzilic acid. First performed by Justus von Liebig in 1838, it is the first reported example of a rearrangement reaction."Nerve Agent Precursors: Benzilic acid and Methyl Benzilate", Factsheets on Chemical and Biological Warfare Agents, Chemical precursors.
|
|
The intermediate is so electrophilic that even neutral nucleophiles can be used, including aromatic rings with electron donating groups such as 1,3-benzodioxole: Example of the Pummerer rearrangement using veratrole It is possible to perform the rearrangement using selenium in the place of sulfur.
|
|
The “1,5 ” hydrogen shift cause transfer of two γ- hydrogen to two radical sites on two different unsaturated atoms. The same requirements for McLafferty rearrangement apply to double-hydrogen rearrangement. This reaction is observed for three unsaturated functional groups, namely thioesters, esters and amides.
|
|
Rearrangements must be carried out at temperatures below −60 °C to avoid competitive [1,2]-rearrangement. Typically, simple treatment of the substrate with n-butyllithium is sufficient to cause rearrangement. Reactions involving butyllithium should be carried out under nitrogen or argon with strict exclusion of water.
|
|
Galaxy Music Corporation: In the Bleak Midwinter by Harold Darke arr. Ronald Arnatt The Darke setting was used in Jacob Collier's rearrangement of the song, which was released on YouTube on 14 December 2016. The rearrangement by Collier features contemporary compositional techniques such as microtonality.
|
|
Rearrangement and substitution in anionotropic systems. Part III. Mechanism of, and equilibrium in, anionotropic change A. G. Catchpole, E. D. Hughes and C. K. Ingold J. Chem. Soc., 1948, 8-17 They were reinvestigating a certain allylic rearrangement reported in 1930 by Jakob Meisenheimer.
|
|
The Chan rearrangement is a chemical reaction that involves rearranging an acyloxy acetate (1) in the presence of a strong base to a 2-hydroxy-3-keto- ester (2). The Chan rearrangement This procedure was rediscovered and employed in the Holton Taxol total synthesis.
|
|
Strongly electron-withdrawing groups suppress the rearrangement pathway, allowing the pericyclic syn elimination pathway to predominate.
|
|
Diazomethane also produces ring enlargement, and its reaction is mechanistically similar to the Tiffeneau-Demjanov rearrangement.
|
|
The two events may occur simultaneously when chromosomal rearrangement is the event that precipates gene birth.
|
|
The mechanistic discussion on whether the vinylcyclopropane rearrangement proceeds through a diradical-mediated two-step or a fully concerted orbital-symmetry-controlled mechanism has been going on for more than half a century. Kinetic data together with the secondary kinetic isotope effects observed at the vinyl terminus of the vinylcyclopropane suggest a concerted mechanism whereas product distribution indicates a stepwise-diradical mechanism. In the 1960s, shortly after the rearrangement was discovered, it was established that the activation energy for the vinylcyclopropane rearrangement is around 50 kcal/mol. The kinetic data obtained for this rearrangement were consistent with a concerted mechanism where cleavage of the cyclopropyl carbon-carbon bond was rate-limiting.
|
|
If Y is nitrogen, the reaction is referred to as the Sommelet–Hauser rearrangement if a quaternary ammonium salt is involved or the aza-Wittig reaction if an alpha-metalated tertiary amine is involved; if Y is oxygen, then it is called a 2,3-Wittig rearrangement (not to be confused with the well-known Wittig reaction, which involves a phosphonium ylide). If Y is sulfur, the product can be treated with a thiophile to generate an allylic alcohol in what is known as the Mislow–Evans rearrangement. center A [2,3]-rearrangement may result in carbon-carbon bond formation. It can also be used as a ring-expansion reaction.
|
|
Typically, the rearrangement is carried out just after the formation of the divinylcyclopropane, in the same pot. Heating is sometimes necessary, particularly for trans substrates, which must undergo epimerization prior to rearrangement. With enough energy to surmount activation barriers, however, the isomerization is usually very efficient.
|
|
In genetics, a chromosomal rearrangement is a mutation that is a type of chromosome abnormality involving a change in the structure of the native chromosome.UniProt. Keyword Chromosomal rearrangement. Accessed 26 Dec 2012. Such changes may involve several different classes of events, like deletions, duplications, inversions, and translocations.
|
|
COT itself—and also analogs with side- chains—have been used as metal ligands and in sandwich compounds. Cyclooctatetraene also undergoes rearrangement reactions to form aromatic ring systems. For instance, oxidation with aqueous mercury(II) sulfate forms phenylacetaldehyde and photochemical rearrangement of its mono-epoxide forms benzofuran.
|
|
During the development of B cells, the immunoglobulin gene undergoes sequences of rearrangements that lead to formation of the antibody repertoire. For example, in the lymphoid cell, a partial rearrangement of the heavy-chain gene occurs which is followed by complete rearrangement of heavy- chain gene. Here at this stage, Pre-B cell, mμ heavy chain and surrogate light chain are formed. The final rearrangement of the light chain gene generates immature B cell and mIgM.
|
|
However, the Wolff rearrangement has limitations due to the highly reactive nature of α-diazocarbonyl compounds, which can undergo a variety of competing reactions. The Wolff rearrangement and subsequent trapping of the ketene intermediate with a weak acid or olefin. The Wolff rearrangement can be induced via thermolysis, photolysis, or transition metal catalysis. In this last case, the reaction is sensitive to the transition metal; silver (I) oxide or other Ag(I) catalysts work well and are generally used.
|
|
A variation of the Zincke reaction has been applied in the synthesis of novel indoles: Zincke aldehydes Kearney 2006 with cyanogen bromide mediated pyridine activation (König method). More recently, an interesting rearrangement of Zincke aldehydes to Z-unsaturated amides was discovered serendipitously while trying to do an intramolecular Diels-Alder reaction. The rearrangement gives the Z-product stereospecifically. In a follow-up paper, allylic amines were used and gave products of a rearrangement / intramolecular Diels-Alder cascade.
|
|
The Cope rearrangement is the prototypical example of a concerted sigmatropic rearrangement. It is classified as a [3,3]-sigmatropic rearrangement with the Woodward-Hoffmann symbol [π2s+σ2s+π2s] and is therefore thermally allowed. It is sometimes useful to think of it as going through a transition state energetically and structurally equivalent to a diradical, although the diradical is not usually a true intermediate (potential energy minimum).Michael B. Smith & Jerry March: March's Advanced Organic Chemistry, pp. 1659-1673.
|
|
2-Butyne can be synthesized by the rearrangement of ethylacetylene in a solution of ethanolic potassium hydroxide.
|
|
Homolysis Heterolysis Two major categories of bond cleavage patterns are simple bond cleavage reactions and rearrangement reactions.
|
|
Two notable explanations for this are incomplete reconnection and rapid rearrangement of flux immediately after a relaxation.
|
|
The Fries rearrangement, named for the German chemist Karl Theophil Fries, is a rearrangement reaction of a phenolic ester to a hydroxy aryl ketone by catalysis of Lewis acids.March, J. Advanced Organic Chemistry, 3rd Ed.; John Wiley & Sons: Chichester, 1985; S. 499ff.Blatt, A. H. Org. React. 1942, 1.
|
|
It was estimated that 90% of all caprolactam is synthesised from cyclohexanone (1), which is first converted to its oxime (2). Treatment of this oxime with acid induces the Beckmann rearrangement to give caprolactam (3): : The Beckmann Rearrangement The immediate product of the acid-induced rearrangement is the bisulfate salt of caprolactam. This salt is neutralized with ammonia to release the free lactam and cogenerate ammonium sulfate. In optimizing the industrial practices, much attention is directed toward minimizing the production of ammonium salts.
|
|
Eugen Bamberger (19 July 1857 – 10 December 1932) was a German chemist and discoverer of the Bamberger rearrangement.
|
|
The Wolff rearrangement is a reaction in organic chemistry in which an α-diazocarbonyl compound is converted into a ketene by loss of dinitrogen with accompanying 1,2-rearrangement. The Wolff rearrangement yields a ketene as an intermediate product, which can undergo nucleophilic attack with weakly acidic nucleophiles such as water, alcohols, and amines, to generate carboxylic acid derivatives or undergo [2+2] cycloaddition reactions to form four-membered rings. The mechanism of the Wolff rearrangement has been the subject of debate since its first use. No single mechanism sufficiently describes the reaction, and there are often competing concerted and carbene-mediated pathways; for simplicity, only the textbook, concerted mechanism is shown below.
|
|
As is the trend with many reactions, conversion of the Z-enolate affords lower selectivity due to 1,3 diaxial steric interactions between the enolate and the ring, as well as the fact that substituents prefer quasi-equatorial positioning. This helps explain the higher temperatures required for Z-enolate conversion. The boat transition state is even less favored by the cationic-2-aza-Cope rearrangement than it is for the Cope rearrangement: in analogous situations to where the Cope rearrangement takes on a boat transition state, the aza-Cope rearrangement continues in the chair geometry. These results are in accord with computational chemistry results, which further assert that the transition state is under kinetic control.
|
|
Phthalimide derivatives were seen to be inactive, while saccharin derivatives were seen to be fair inhibitors of these enzymes. Gabriel-Colman Rearrangement Example 1 In a study of the derivatives of 3-Oxo-1,2-benzoisothiazoline-2-acetic acid 1,1-dioxide, the Gabriel–Colman rearrangement was employed in the conversion of Isopropyl (1,1-dioxido-3-oxo-1,2-benzothiazol-2(3H)-yl)acetate to Isopropyl 4-hydroxy-2H-1,2-benzothiazine-3-carboxylate 1,1-dioxide, as shown above. This reaction has shown a percent yield of 85%. Gabriel-Colman Rearrangement Example 2 In another study, N-phthalimidoglycine ethyl ester was used to synthesize 4-hydroxyisoquinoline through use of a Gabriel–Colman rearrangement, as shown above.
|
|
When heated, the pi-system goes through an electrocyclic ring closing to form bicycle[4,1,0]heptadiene (norcaradiene). Thereafter follows a [1,5] alkyl shift and an electrocyclic ring opening. :norcaradiene rearrangement Proceeding through a [1,5] shift, the walk rearrangement of norcaradienes is expected to proceed suprafacially with a retention of stereochemistry.
|
|
Protection Reagent: Phosgene, pyridine, dichloromethane, -78 °C to room temperature, 1 h. Deprotection Reagents: deprotected through Chan rearrangement (treatment with lithiumtetramethylpiperidide). The cyclic carbonate ester was removed as a result of the Chan rearrangement in 15, which created a carbon-carbon bond that was part of the Taxol framework (Scheme 2).
|
|
Fries is noted for the discovery of the Fries rearrangement, which is an important reaction used in Organic synthesis.
|
|
In 1983 regional offices were established in the then 4 divisions including Dhaka as the headquarter by divisional rearrangement.
|
|
It was opened to the public on June 14, 1980 after rearrangement of the exhibition items in chronological order.
|
|
Typical types of chemical damage reactions that can occur to metabolites are racemization, rearrangement, elimination, photodissociation, addition, and condensation.
|
|
The Wolff rearrangement has been used in many total syntheses; the most common use is trapping the ketene intermediate with nucleophiles to form carboxylic acid derivatives. The Arndt-Eistert homologation is a specific example of this use, wherein a carboxylic acid may be elongated by a methylene unit. Another common use is in ring-contraction methods; if the α-diazo ketone is cyclic, the Wolff rearrangement results in a ring-contracted product. The Wolff rearrangement works well in generating ring-strained systems, where other reactions may fail.
|
|
The “1,5 ” hydrogen shift cause transfer of two γ- hydrogen to two radical sites on two different unsaturated atoms. The same requirements for The “1,5 ” hydrogen shift occur between proper substituents in the ortho positions of the aromatic rings. The same requirements for McLafferty rearrangement apply to ortho rearrangement except for the strong α,β carbon- carbon double bond. Such rearrangement initiates charge-site reaction, resulting in the formation of an odd electron ion and a small neutral molecule ( water, or HCl and so on).
|
|
In the solvolysis of methyl substituted cyclohexenyl triflate, the rearrangement and non-rearranged product are formed in almost equal amounts, with a small preference to the rearrangement product because of its linear structure. However, it must be noted that there is some strain in the methylenesyclopentane rearrangement product. Lastly, halogens could also move into and stabilize a vinyl cation system. In the reaction of 5-chloropentyne with trifluoroacetic acid, there is simultaneous protonation and 1,4-shift of chlorine that forms a bridge cyclic structure across four carbons.
|
|
Julius Stieglitz (May 26, 1867 – January 10, 1937) was an American chemist of German Jewish origin. He was a teacher and organic chemist with a major interest in pharmaceutical and medicinal chemistry. He is known for the Stieglitz rearrangement, a rearrangement reaction in organic chemistry which commonly involves the formation of imines from hydroxylamines through a carbon to nitrogen shift, comparable to the key step of a Beckmann rearrangement. During the early stages of his career, he worked for Parke, Davis & Co. in Detroit as a toxicologist.
|
|
He is a co-founder of two start-up companies, Orbit Discovery and of Quadrucept Bio. His research has focussed on antibody and T cell receptor gene diversity, gene rearrangement and aberrant rearrangement of chromosomes (chromosomal translocations) in cancer. He pioneered the method of cDNA cloning, an approach universally used in bioscience and biotechnology, and elucidated the organization, diversity and rearrangement of human antibody genes, which defined the building blocks for construction of therapeutic antibody repertoires. He also pioneered chimaeric antibodies (with the late Michael Neuberger).
|
|
Horowitz and Geissman's first example demonstrates a possible thermodynamic sink to couple with the cationic 2-aza-Cope rearrangement, where the product is biased by the phenyl substituent through aryl conjugation, then captured by hydrolysis of the iminium. Other methods of biasing a product include using substituents which are more stable on substituted carbons, releasing ring strain (for instance, by pairing the rearrangement with cyclopropane opening), intramolecular trapping (pictured), and pairing the rearrangement with the Mannich cyclization. The iminium is trapped by the intramolecular nucleophile.
|
|
Hofmann received several significant awards in the field of chemistry, including the Royal Medal (1854), the Copley Medal (1875) and the Albert Medal (1881). He was ennobled on his seventieth birthday. His name is associated with the Hofmann voltameter, the Hofmann rearrangement, the Hofmann–Martius rearrangement, Hofmann elimination, and the Hofmann–Löffler reaction.
|
|
The Hofmann rearrangement is the organic reaction of a primary amide to a primary amine with one fewer carbon atom. The Hofmann rearrangement. The reaction is named after its discoverer – August Wilhelm von Hofmann. This reaction is also sometimes called the Hofmann degradation, and should not be confused with the Hofmann elimination.
|
|
The primary debate concerning the mechanism of the rearrangement centers on whether it is a concerted (sigmatropic) or stepwise (diradical) process. Mechanistic experiments have shown that trans-divinylcyclopropanes epimerize to the corresponding cis isomers and undergo the rearrangement via what is most likely a concerted pathway.Arai, M.; Crawford, R. J. Can. J. Chem.
|
|
Levuglandins are reactive aldehydes formed by the spontaneous rearrangement of prostaglandin H (PGH). Enantiomerically pure levuglandin (LG) E2 can also be formed through the cyclooxygenase (COX) pathway by a rearrangement of the prostaglandin (PG) endoperoxide PGH 2. They are nonclassic eicosanoids. One species, levuglandin E2, (LGE2), forms neurotoxic adducts with amyloid beta.
|
|
Examples include tetramethylammonium pentafluoroxenate, containing the highly reactive pentafluoroxenate () ion. Permanganate can be solubilized in organic solvents, when deployed as its salt. With exceptionally strong bases, quat cations degrade. They undergo Sommelet–Hauser rearrangement and Stevens rearrangement, as well as dealkylation under harsh conditions or in presence of strong nucleophiles, like thiolates.
|
|
In the resulting rearrangement to create monophyletic genera the blue-lored antbird was moved to the newly erected genus Hafferia.
|
|
Upon photolysis, DNQ undergoes a Wolff rearrangement to form a ketene. The ketene adds water to form indane-carboxylic acid.
|
|
2-Pentyne can be synthesized by the rearrangement 1-pentyne in a solution of ethanolic potassium hydroxide or NaNH2/NH3.
|
|
Organic Reaction Mechanisms. Harrow, U.K.: Alpha Science International, 2005. Print. :Sommelet-Hauser mechanism The Stevens rearrangement is a competing reaction.
|
|
The Amadori rearrangement is an organic reaction describing the acid or base catalyzed isomerization or rearrangement reaction of the N-glycoside of an aldose or the glycosylamine to the corresponding 1-amino-1-deoxy- ketose.Strategic Applications of Named Reactions in Organic Synthesis (Paperback) by Laszlo Kurti, BN 0-12-429785-4 The reaction is important in carbohydrate chemistry, specifically the glycation of hemoglobin (as measured by the HbA1c test). The rearrangement is usually preceded by formation of a α-hydroxyimine by condensation of an amine with an aldose sugar. The rearrangement itself entails intramolecular redox reaction, converting this α-hydroxyimine to an α-ketoamine: :center The formation of imines is generally reversible, but subsequent to conversion to the keto-amine, the attached amine is fixed irreversibly.
|
|
The rearrangement is widely used in organic synthesis. It is symmetry-allowed when it is suprafacial on all components. The transition state of the molecule passes through a boat or chair like transition state. An example of the Cope rearrangement is the expansion of a cyclobutane ring to a cycloocta-1,5-diene ring: File:3,3copeexpansion.
|
|
The Newman–Kwart rearrangement is a type of rearrangement reaction in which the aryl group of an O-aryl thiocarbamate, ArOC(=S)NMe2, migrates from the oxygen atom to the sulfur atom, forming an S-aryl thiocarbamate, ArSC(=O)NMe2. The reaction is named after its discoverers, Melvin Spencer Newman and Harold Kwart. 400px The Newman–Kwart rearrangement is one of the most important ways of synthesising thiophenols. A phenol (1) is deprotonated with a base such as DABCO or NaH and reacted with a thiocarbamoyl chloride (2) to form an O-aryl thiocarbamate (3).
|
|
The Kornblum–DeLaMare rearrangement is a rearrangement reaction in organic chemistry in which a primary or secondary organic peroxide is converted to the corresponding ketone and alcohol under acid or base catalysis. The reaction is relevant as a tool in organic synthesis and is a key step in the biosynthesis of prostaglandins.The base catalyzed decomposition of a dialkyl peroxide Nathan Kornblum and Harold E. DeLaMare J. Am. Chem. Soc.; 1951; 73(2) pp 880–81; () :Kornblum–DeLaMare rearrangement overview The base can be a hydroxide such as potassium hydroxide or an amine such as triethylamine.
|
|
The Tiffeneau–Demjanov rearrangement (TDR) is the chemical reaction of a 1-aminomethyl-cycloalkanol with nitrous acid to form an enlarged cycloketone. The Tiffeneau–Demjanov rearrangement The Tiffeneau–Demjanov ring expansion, Tiffeneau–Demjanov rearrangement, or TDR, provides an easy way to increase amino-substituted cycloalkanes and cycloalkanols in size by one carbon. Ring sizes from cyclopropane through cyclooctane are able to undergo Tiffeneau–Demjanov ring expansion with some degree of success. Yields decrease as initial ring size increases, and the ideal use of TDR is for synthesis of five, six, and seven membered rings.
|
|
Secondary hydrogen isotope effects from the methylene hydrogens were also used to show that Cope rearrangement in 1,5-hexadiene follow a concerted bond rearrangement pathway, and not one of the alternatively proposed allyl radical or 1,4-diyl pathways, all of which are presented in the following scheme. 400px Alternative mechanisms for the Cope rearrangement of 1,5-hexadiene: (from top to bottom), allyl radical, synchronous concerted, and 1,4-dyil pathways. The predominant pathway is found to be the middle one, which has six delocalized π electrons corresponding to an aromatic intermediate.
|
|
An important use of the Piancatelli rearrangement that was studied by Piancatelli himself is the synthesis of prostaglandins and their derivatives. Piancatelli was able to synthesize key intermediates for the preparation of prostanoic acid starting from his 2-furylcarbinols bearing a second functional group. This study was able to demonstrate the versatility of the sequence of the rearrangement. A few of the products synthesized due to utilizing the Piancatelli rearrangement include: 3E,5Z-misoprostol, enisoprost, 4-fluoro- enisoprost, 2-normisoprostol, prostaglandin E1 (PGE1), ent-phytoprostane E1, 16-epi-phytoprostane E1, bimatoprost, and travoprost.
|
|
The reaction mechanism of the Stevens rearrangement is one of the most controversial reaction mechanisms in organic chemistry. Key in the reaction mechanismM B Smith, J March. March's Advanced Organic Chemistry (Wiley, 2001) ()Strategic Applications of Named Reactions in Organic Synthesis Laszlo Kurti, Barbara Czako Academic Press (4 March, 2005) for the Stevens rearrangement (explained for the nitrogen reaction) is the formation of an ylide after deprotonation of the ammonium salt by a strong base. Deprotonation is aided by electron- withdrawing properties of substituent R. Several reaction modes exist for the actual rearrangement reaction.
|
|
The reaction was discovered by Ludwig Wolff in 1902. The Wolff rearrangement has great synthetic utility due to the accessibility of α-diazocarbonyl compounds, variety of reactions from the ketene intermediate, and stereochemical retention of the migrating group.Gill, G. B. (1991) “The Wolff Rearrangement.” in Trost, B. M. Flemming, I. (eds.) Comp. Org. Synth. Oxford: Pergamon. 3:887. .
|
|
The mechanism of the Pratt diene rearranging; note the regioselectivity 550px The barrelene rearrangement is now presented. It is a bit more complex than the Mariano and Pratt examples since there are two sp3-hybridized (i.e. methane) carbons. Each such bridgehead carbon has three (ethylenic) pi bonds while two are needed for the di-pi-methane rearrangement.
|
|
The rearrangement of chromosome 22 involves intron 8 of EWS and exon 1 of this gene creating a chimeric sequence containing the transactivation domain of EWS fused to zinc finger domain of this protein. This is a distinct example of an intra-chromosomal rearrangement of chromosome 22. Four alternatively spliced transcript variants are described for this gene.
|
|
Migratory aptitude is the relative ability of a migrating group to migrate in a rearrangement reaction. Migratory aptitudes vary in different reactions, depending on multiple factors. In the Baeyer-Villiger reaction, the more substituted group, in general, migrates. In the pinacol rearrangement, the order of migratory aptitude has not been determined unambiguously, but some trends have been determined.
|
|
In academic research, trichloroacetonitrile is used as a reagent in the Overman rearrangement, converting allylic alcohols into allylic amines. The reaction is based on a [3,3]-sigmatropic and diastereoselective rearrangement. Benzyl trichloroacetimidate is easily accessible from benzyl alcohol and trichloroacetonitrile. Benzyl trichloroacetimidate is useful as a benzylating reagent for sensitive alcohols under mild conditions and to preserve chirality.
|
|
In the oxy-Cope rearrangement a hydroxyl group is added at C3 forming an enal or enone after Keto-enol tautomerism of the intermediate enol.A Synthesis of Ketones by the Thermal Isomerization of 3-Hydroxy-1,5-hexadienes. The Oxy-Cope Rearrangement Jerome A. Berson, Maitland Jones, , Jr. J. Am. Chem. Soc. 1964; 86(22); 5019–5020.
|
|
PtdIns(3,4,5)P3 also activates guanine‐nucleotide exchange factors (GEFs) that activate the GTPase Rac1, leading to actin polymerization and cytoskeletal rearrangement.
|
|
Several differences from TEA are apparent, including a somewhat more complex key-schedule and a rearrangement of the shifts, XORs, and additions.
|
|
The key steps are a photocatalyzed intramolecular [2 + 2] cycloaddition reaction followed by a rearrangement reaction which forms three contiguous chiral centers.
|
|
The Claisen rearrangement of aryl ethers can also be performed as a photochemical reaction. In addition to the traditional ortho product obtained under thermal conditions (the [3,3] rearrangement product), the photochemical variation also gives the para product ([3,5] product), alternate isomers of the allyl group (for example, [1,3] and [1,5] products), and simple loss of the ether group, and even can rearrange alkyl ethers in addition to allyl ethers. The photochemical reaction occurs via a stepwise process of radical-cleavage followed by bond-formation rather than as a concerted pericyclic reaction, which therefore allows the opportunity for the greater variety of possible substrates and product isomers. The [1,3] and [1,5] results of the photo- Claisen rearrangement are analogous to the photo-Fries rearrangement of aryl esters and related acyl compounds.
|
|
Enyne cycloisomerization, an alkyne variant of the Alder-ene reaction (figure 5), is an intramolecular rearrangement of 1,n–enynes to give the corresponding cyclic isomer. center Although the rearrangement may occur under thermal conditions, the scope of the thermal rearrangement is limited due to the requirement of high temperatures, thus transition metals such as Au, Pd, Pt, Rh and Ir are often employed as catalysts. As synthesis quarrels to build complex structural motifs in the presence of inductive, stereoelectronic and steric demands this rearrangement has recently been developed as a robust method for constructing carbo– and heterocyclic scaffolds with excellent chemo–, regio– and diastereoselective outcomes. There is not a single mechanism that can be used to describe enyne cycloisomerizations as the mechanism depends on reaction conditions and catalyst selection.
|
|
This process is repeated for the joining of V to DJ. In light-chain rearrangement, only V and J segments are brought together.
|
|
Finally, the relabelling operations commute with the rearrangement operations, so the full soduku (VPT) group is (S3 ≀ S3 ≀ C2) × S9 of order 1,218,998,108,160.
|
|
The Smiles rearrangement is an organic reaction and a rearrangement reaction named after british chemist Samuel Smiles. It is an intramolecular nucleophilic aromatic substitution of the type: Smiles rearrangement where X in the arene compound can be a sulfone, a sulfide, an ether or any substituent capable of dislodging from the arene carrying a negative charge. The terminal functional group in the chain end Y is able to act as a strong nucleophile for instance an alcohol, amine or thiol. As in other nucleophilic aromatic substitutions the arene requires activation by an electron-withdrawing group preferably in the aromatic ortho position.
|
|
If the reactant is a cyclic α-diazo ketone, then Wolff-rearrangement products will be the one-carbon ring-contracted product. These reactions are generally concerted due to the s-cis conformation, and are photocatalyzed. The reaction below shows the concerted mechanism for the ring contraction of α-diazocyclohexanone, followed by trapping of the ketene with a weakly acidic nucleophile. Ring contraction of α-diazocyclohexanone via Wolff-rearrangement The first known example is the ring contracted Wolff rearrangement product of α-diazocamphor, and subsequent kinetic hydration of the ketene from the more sterically accessible "endo" face, to give exo-1,5,5-trimethylbicyclo[2.1.
|
|
The Fischer–Hepp rearrangement is a rearrangement reaction in which an aromatic N-nitroso or nitrosamine converts to a carbon nitroso compound:O Fischer, E Hepp. Ber Deutsch chem Ges 19 (1886) p2991M B Smith, J March. March's Advanced Organic Chemistry (Wiley, 2001) () Fischer-Hepp rearrangement This organic reaction was first described by the German chemist Otto Philipp Fischer (1852–1932 ) and Eduard Hepp (June 11, 1851 – June 18, 1917) W Pötsch. Lexikon bedeutender Chemiker (VEB Bibliographisches Institut Leipzig, 1989) in 1886, and is of importance because para-NO secondary anilines cannot be prepared in a direct reaction.
|
|
However, in vinyl cations, this rearrangement is uncommon even though the rearrangement product in thermodynamically stable. Much like the aryl- substituted vinyl cations, the interacting orbitals during the conversion of a linear vinyl cation to a non-linear allyl cation are orthogonal and passes through a non-planar transition state, which makes the rearrangement difficult. This is evident in the higher activation energies of 1,2-hydride shifts in vinyl cations compared to alkyl cations. Examples of reactions in which this is observed would be the protonation of di-alkyl substituted alkynes and in the solvolysis of ispropylvinyl trifluromethanesulfonate in trifluoroethanol.
|
|
In contrast to the Claisen rearrangement, Cope rearrangements without strain release or electronic perturbation are often close to thermally neutral, and may therefore reach only partial conversion due to an insufficiently favorable equilibrium constant. In the case of hexa-1,5-diene, the rearrangement is degenerate (the product is identical to the starting material), so K = 1 by necessity. 176x176px In asymmetric dienes one often needs to consider the stereochemistry, which in the case of pericyclic reactions, such as the Cope rearrangement, can be predicted with the Woodward-Hoffmann rules and consideration of the preference for the chair transition state geometry.
|
|
Research has shown that the Curtius rearrangement is catalyzed by both Brønsted and Lewis acids, via the protonation of, or coordination to the acyl oxygen atom respectively. For example, Fahr and Neumann have shown that the use of boron trifluoride or boron trichloride catalyst reduces the decomposition temperature needed for rearrangement by about 100 °C, and increases the yield of the isocyanate significantly.
|
|
R. B. Woodward et al. used the Curtius rearrangement as one of the steps in the total synthesis of the polyquinane triquinacene in 1964. Following hydrolysis of the ester in the intermediate (1), a Curtius rearrangement was effected to convert the carboxylic acid groups in (2) to the methyl carbamate groups (3) with 84% yield. Further steps then gave triquinacene (4).
|
|
It was also observed, that the addition of lead tetraacetate can facilitate the Stieglitz rearrangement of amine derivatives. After the formation of the activated amine derivative intermediate by coordination to the lead center, the following rearrangement again proceeds via migration of the aromatic group under formation of a C-N bond, dissociation of lead and the deprotonation of the resulting iminium ion.
|
|
His research continued at Harvard University in 1933 as a National Research Council Fellow. In 1934, he joined the faculty of Bryn Mawr College. There, his research included the first syntheses of a number of barbiturates including delvinyl sodium. At Bryn Mawr, Cope also developed a reaction involving the thermal rearrangement of an allyl group which eventually became known as the Cope rearrangement.
|
|
Propargyl alcohol polymerizes with heating or treatment with base. It is used as a corrosion inhibitor, a metal complex solution, a solvent stabilizer and an electroplating brightener additive. It is also used as an intermediate in organic synthesis. Secondary and tertiary substituted propargylic alcohols undergo catalyzed rearrangement reactions to form α,β-unsaturated carbonyl compounds via the Meyer–Schuster rearrangement and others.
|
|
In a similar fashion, the intermediate isocyanate can be trapped by tert-butyl alcohol, yielding the tert-butoxycarbonyl (Boc)-protected amine. The Hofmann Rearrangement also can be used to yield carbamates from α,β-unsaturated or α-hydroxy amides or nitriles from α,β-acetylenic amides in good yields (≈70%). For amiloride, hypobromous acid was used to effect a Hofmann rearrangement.
|
|
N-oxides are prone to undergo the Polonovski rearrangement when treated with acetic anhydride, and this was illustrated by the synthesis of oxazepam. It is not surprising that the N-methyl analogue (1) also undergoes this process, and hydrolysis of the resulting acetate gives temazepam (2). Care must be exacted with the conditions, or the inactive rearrangement product (3) results.
|
|
Ketol isomerizations of secondary α-hydroxy carbonyl compounds, which proceed via tautomerization, are probably the closest relative of the α-ketol rearrangement discussed here. Also closely related are carbohydrate rearrangements such as the Lobry–de Bruyn–van Ekenstein transformation,Angyal, S. J. Top. Curr. Chem., 2001, 215, 1. which involve conversion to the open form followed by rearrangement and re-closing.
|
|
The aza-Cope/Mannich reaction The aza- Cope/Mannich reaction is a synthetically powerful reaction, as it is able to create complex cyclic molecules from simple starting materials. This tandem reaction provides a thermodynamic bias towards one rearrangement product, as the Mannich cyclization is irreversible and its product, an acyl substituted pyrrolidine ring, more stable than that of the rearrangement.
|
|
Ando and Fisher define a completely decomposable matrix as one where "an identical rearrangement of rows and columns leaves a set of square submatrices on the principal diagonal and zeros everywhere else." A nearly completely decomposable matrix is one where an identical rearrangement of rows and columns leaves a set of square submatrices on the principal diagonal and small nonzeros everywhere else.
|
|
An unaffected person can carry a rearrangement of genetic material between chromosome 13 and another chromosome. This rearrangement is called a balanced translocation because there is no extra material from chromosome 13. Although they do not have signs of Patau syndrome, people who carry this type of balanced translocation are at an increased risk of having children with the condition.
|
|
The Sommelet–Hauser rearrangement (named after M. SommeletM. Sommelet, Compt. Rend. 205, 56 (1937). and Charles R. HauserRearrangements of Benzyltrimethylammonium Ion and Related Quaternary Ammonium Ions by Sodium Amide Involving Migration into the Ring Simon W. Kantor, Charles R. Hauser J. Am. Chem. Soc., 1951, 73 (9), pp 4122–4131 ) is a rearrangement reaction of certain benzyl quaternary ammonium salts.
|
|
Fitting of the dynamic NMR process ruled out the sandwich species even as an intermediate in the 20-fold degenerate rearrangement of the carbocation.
|
|
The Southern Mystique was in large part a rearrangement of Zinn's previous writings, with only fifty of the book's 270 pages being entirely new.
|
|
Mitragynine pseudoindoxyl is a rearrangement product of 7-hydroxymitragynine. It is an analgesic being more potent than morphine and about as potent as enkephalin.
|
|
Conditions for the rearrangement of α-hydroxy imines are similar, although the resulting amino ketone products are usually isolated as the corresponding acid salts.
|
|
The reaction is named after the Russian chemist Yegor Yegorovich Vagner; he had German origin and published in German journals as Georg Wagner; and Hans Meerwein. Several reviews have been published. The rearrangement was first discovered in bicyclic terpenes for example the conversion of isoborneol to camphene: 1000px The story of the rearrangement reveals that many scientists were puzzled with this and related reactions and its close relationship to the discovery of carbocations as intermediates. In a simple demonstration reaction of 1,4-dimethoxybenzene with either 2-methyl-2-butanol or 3-methyl-2-butanol in sulfuric acid and acetic acid yields the same disubstituted product, the latter via a hydride shift of the cationic intermediate: :Carbocation rearrangement Polito 2010 Currently, there are works relating to the use of skeletal rearrangement in the synthesis of bridged azaheterocycles.
|
|
Seeberger, P.H., et al. Aldrichimica Acta 30, 75, (1997) Glucal and its derivatives can be converted to other chemically useful sugars using the Ferrier rearrangement.
|
|
Menthofuran can be synthesized from 5-methylcyclohexane-1,3-dione and allenyldimethylsulfonium bromide in two steps via a furannulation strategy consisting of enolate addition and rearrangement.
|
|
The Claisen rearrangement is an exothermic, concerted (bond cleavage and recombination) pericyclic reaction. Woodward–Hoffmann rules show a suprafacial, stereospecific reaction pathway. The kinetics are of the first order and the whole transformation proceeds through a highly ordered cyclic transition state and is intramolecular. Crossover experiments eliminate the possibility of the rearrangement occurring via an intermolecular reaction mechanism and are consistent with an intramolecular process.
|
|
After carbanion formation, the [2,3]-Wittig rearrangement is rapid and selective at low temperatures. However, if the reaction mixture is allowed to reach temperatures above −60 °C, [1,2]-rearrangement becomes competitive. (2)File:23Mech1.png The postulated transition state possesses a five-membered, envelope-like structure. The group attached to the carbanion (G) can occupy either a pseudoequatorial or pseudoaxial position, although the former is usually preferred.
|
|
In the presence of butylated hydroxytoluene (BHT) used as a radical scavenger, a toluene solution of the adduct between geraniol and camphorsultam was heated in a sealed tube at 140 °C, to provide mainly the (2R,3S)-isomer as the major rearrangement product in 72% yield, securing the two contiguous stereocenters including the quaternary carbon. Camphorsultam was used as a chiral auxiliary in Claisen rearrangement.
|
|
Carboxamides, in which the amide is attached to the aromatic ring through nitrogen rather than carbon, are also effective directing groups.Fuhrer, W.; Gschwend, H. W. J. Org. Chem. 1979, 44, 1133. (5)File:LatLithScope2.png Related O-aryl carbamates are good directing groups; upon warming, the resulting organolithiums undergo rearrangement to benzylic amides (the Snieckus-Fries rearrangement) via migration of the carbonyl carbon from oxygen to carbon.
|
|
Elemicin has been synthesized from syringol and allyl bromide using Williamson ether synthesis and Claisen rearrangement. The electrophilic aromatic substitution entering the para- position was made possible by secondary Cope rearrangement. This is due to syringol's allyl aromatic ether being blocked by ethers in both ortho- positions. When blocked the allyl group migrates to the para-position, in this case with yields above 85%.
|
|
This leads to further rearrangement and subsequent hydrolysis, ultimately resulting in the formation of an aldehyde bearing the next amino acid residue in the sequencing series and the expulsion of the residual peptide in amide form. Mechanism of the Bergmann degradation A mechanism has been proposed which depicts catalytic hydrogenation of the benzylurethane as a concerted rearrangement that releases carbon dioxide concomitantly with formation of the amide.
|
|
Vinyl oxazolidines can also be used as rearrangement substrates. This rearrangement first creates the vinyl oxazolidine from attack on the cyclohexanone by the aminobutenol, which then undergoes the aza-Cope/Mannich reaction using heat and acid (Lewis or protic). This example breaks and then forms a five-membered ring. More complex examples attach the oxazolidine to another ring, presenting additional methods for the formation of indolizidine cycles.
|
|
Zincke-Suhl products can be used as starting reagents for the dienol benzene rearrangement. This is an important reaction for artificially producing biologically relevant molecules including the A ring of steroids. Dienol Benzene Rearrangement Perhaps the most intriguing application of the Zincke–Suhl reaction is its potential following von Auwers rearrangements. Demeunier and Jaeckh described how such rearrangements may result in the formation of high energy intermediates.
|
|
It is a positive regulator for gene transcription. It has been shown that associates with Host cell facor C1, CREB binding protein, WDR5, CTBP, MEN1, etc. The rearrangement of MLL are related with different kinds of aggressive acute leukemias. Most of biphenotypic leukemia in children is due to the rearrangement of MLL Protein MLL PDB 2j2s Besides them, other gene abnormalities has been reported.
|
|
It has been suggested that the rearrangement, after the dissociation of the N2 molecule, proceeds over a reactive nitrene intermediate. These intermediates would be quite similar to those that have been proposed to be key intermediates in the rearrangement reactions named after Hofmann and Curtius, but have since been considered unlikely. When subjecting the azide to a Brønsted acid, the protonation of the azide activates the basal nitrogen and lowers the bond strength to the adjacent one, so that the dissociation and expulsion of molecular nitrogen is eased. After the rearrangement the proton can then dissociate from the iminium ion to yield the imine.
|
|
Brook Rearrangement In the late 1950s, Adrian Brook discovered a rearrangement reaction in organosilicon chemistry that was later named the Brook rearrangement. He also synthesized the first stable compounds containing silicon-carbon double bonds. Photodegradable Plastics While attempting to create polymers that were less resistant to ultraviolet rays from the sun, Jim Guillet discovered, through a Norrish reaction, a process for making plastics (such as foam coffee cups and fast food clam-shell containers) decompose in sunlight. Frustrated Lewis Pairs Douglas Stephan is the pioneer of the Frustrated Lewis pair, a compound or mixture containing a Lewis acid and a Lewis base that cannot combine to form a classical adduct.
|
|
Many important inequalities can be proved by the rearrangement inequality, such as the arithmetic mean – geometric mean inequality, the Cauchy–Schwarz inequality, and Chebyshev's sum inequality.
|
|
Originally, it was held that chromosome rearrangement would play an important role.Darlington, C.D.; Mather, K. 1949. The Elements of Genetics, pp. 335–336. London: Allen & Unwin.
|
|
Other common ylides include sulfonium ylides and sulfoxonium ylides, for instance the Corey-Chaykovsky reagent used in the preparation of epoxides or in the Stevens rearrangement.
|
|
Rossberg et al. “Chlorinated Hydrocarbons” in Ullmann’s Encyclopedia of Industrial Chemistry 2006, Wiley- VCH, Weinheim. :CH4 \+ Cl2 → CH3Cl + HCl Rearrangement often accompany such free radical reactions.
|
|
Notta, Faiyaz, et al. "A renewed model of pancreatic cancer evolution based on genomic rearrangement patterns." Nature538.7625 (2016): 378. Pancreatic cancer is a rapidly progressing cancer.
|
|
In the resulting rearrangement to create monophyletic genera the northern chestnut-tailed antbird and the southern chestnut-tailed antbird were moved to a newly erected genus Sciaphylax.
|
|
In the resulting rearrangement to create monophyletic genera the southern chestnut-tailed antbird and the northern chestnut-tailed antbird were moved to a newly erected genus Sciaphylax.
|
|
Map of Girl Scout Councils in New Jersey New Jersey is divided into four councils that were created by rearrangement of the previous eleven councils in 2007.
|
|
The defining feature of NMCs is rearrangement of the NUT gene. Most common is a translocation involving the BRD4 gene and NUT gene (t(15;19)(q13;p13.1)).
|
|
Grin's music director Erik Thunberg was responsible for the game's score, including a track that features a rearrangement of the "Prelude" theme from the Final Fantasy series.
|
|
Loose heme can cause oxidation of endothelial and LDL proteins, which results in plaques. Glycation pathway via Amadori Rearrangement (in HbA1c, R is typically N-terminal valine).
|
|
Metal- ion-catalyzed σ-bond rearrangement These rearrangements proceed via oxidative addition of strained rings. Such processes are related to the activation of cyclopropanes by transition metals.
|
|
MTOCs are not found in plant cells. Plant viruses induce the rearrangement of membranes structures to form the viroplasm. This is mostly shown for plant RNA viruses.
|
|
Phase change metamorphism is the creating of new minerals with the same chemical formula as the protolith. This involves a rearrangement of the atoms in the crystals.
|
|
Bhavani is part of the Tiruppur Lok Sabha constituency in Tamil Nadu. Earlier, before the rearrangement of constituencies in 2008, it was part of the Gobichettipalayam constituency.
|
|
Wittig's contributions also include the preparation of phenyllithium and the discovery of the 1,2-Wittig rearrangement and the 2,3-Wittig rearrangement. Wittig was well known in the chemistry community for being a consummate experimenter and observer of chemical transformations, while caring very little for the theoretical and mechanistic underpinnings of the work he produced. Georg also has his name on a literature work titled on a compound labelled Colopidalol.
|
|
Chemical reactions can result in the formation or dissociation of molecules, that is, molecules breaking apart to form two or more molecules or rearrangement of atoms within or across molecules. Chemical reactions usually involve the making or breaking of chemical bonds. Oxidation, reduction, dissociation, acid-base neutralization and molecular rearrangement are some of the commonly used kinds of chemical reactions. A chemical reaction can be symbolically depicted through a chemical equation.
|
|
The Meyer–Schuster rearrangement is the chemical reaction described as an acid-catalyzed rearrangement of secondary and tertiary propargyl alcohols to α,β-unsaturated ketones if the alkyne group is internal and α,β-unsaturated aldehydes if the alkyne group is terminal.Meyer, K. H.; Schuster, K. Ber. 1922, 55, 819.() Reviews have been published by Swaminathan and Narayan,Swaminathan, S.; Narayan, K. V. "The Rupe and Meyer-Schuster Rearrangements" Chem. Rev.
|
|
Meyer-Schuster Rearrangement The reaction mechanismLi, J.J. In Meyer-Schuster rearrangement; Name Reactions: A Collection of Detailed Reaction Mechanisms; Springer: Berlin, 2006; pp 380–381.() begins with the protonation of the alcohol which leaves in an E1 reaction to form the allene from the alkyne. Attack of a water molecule on the carbocation and deprotonation is followed by tautomerization to give the α,β-unsaturated carbonyl compound. Edens et al.
|
|
Jerry March Substituted cyclopropanes can oxidatively add to transition metals, in a process referred to as C–C activation. :Electrophilic addition of HBr to cyclopropane Cyclopropyl groups adjacent to vinyl groups can undergo ring expansion reactions. Examples include the vinylcyclopropane rearrangement and the divinylcyclopropane-cycloheptadiene rearrangement. This reactivity can be exploited to generate unusual cyclic compounds, such as cyclobutenes, or bicyclic species such as the cycloheptene shown below.
|
|
The halogen dance rearrangement is an organic reaction in which a halogen substituent moves to a new position on an aromatic ring system. The reaction belongs to a class of organic reactions called 1,2-rearrangements. The original halogen dance is the base-catalysed rearrangement of 1,2,4-tribromobenzene to 1,3,5-tribromobenzene in liquid ammonia with the aniline/potassium base system. The intermediate in this reaction is an aryl carbanion.
|
|
However, low concentrations of a radical scavenger establish thermodynamic control and provide access to 6-endo products—not via 6-endo cyclization, but by 5-exo cyclization followed by 3-exo closure and subsequent fragmentation (Dowd-Beckwith rearrangement). Whereas at high concentrations of the exo product is rapidly trapped preventing subsequent rearrangement to the endo productBeckwith, A.; O'Shea, D. Tetrahedron Lett. 1986, 27, 4525. Aryl radicals exhibit similar reactivity.
|
|
The divinylcyclopropane-cycloheptadiene rearrangement is an organic chemical transformation that involves the isomerization of a 1,2-divinylcyclopropane into a cycloheptadiene or -triene. It is conceptually related to the Cope rearrangement, but has the advantage of a strong thermodynamic driving force due to the release of ring strain. This thermodynamic power is recently being considered as an alternative energy source.Hudlicky, T.; Fan, R.; Reed, J. W.; Gadamasetti, K. G. Org. React.
|
|
The Favorskii rearrangement is the poster child of the anionic ring contractions. It proceeds through a carbanion which attacks an endocyclic carbon and expels a leaving group (a halide) forming a bicyclic molecule with rings smaller than the original. The bicycle is then opened by nucleophilic attack on the ketone to give the contracted product. A generalized mechanism of the Favorskii rearrangement to give a ring contracted product.
|
|
The McLafferty rearrangement is a reaction observed in mass spectrometry during the fragmentation or dissociation of organic molecules. It is sometimes found that a molecule containing a keto-group undergoes β-cleavage, with the gain of the γ-hydrogen atom, as first reported by Nicholson working in the Division of Chemical Physics at the CSIRO in Australia. This rearrangement may take place by a radical or ionic mechanism.
|
|
Neuroplasticity refers to the ability of the brain to undergo synaptic rearrangement as a response to recurring stimuli. Neurotrophin proteins play a major role in synaptic rearrangement, amongst other factors. Depletion of neurotrophin BDNF or BDNF signaling is one of the main factors in developing diseases such as Alzheimer's disease, Huntington's disease, and depression. Neuroplasticity can also occur as a consequence of targeted epigenetic modifications such as methylation and acetylation.
|
|
Mechanistic studies revealed that the rearrangement did indeed proceed via a concerted, Cope-type mechanism.Vogel, E.; Ott, K.-H.; Gajek, K. Justus Liebigs Ann. Chem. 1961, 644, 172.
|
|
Numerous chemical targets have distinct stereochemical demands. Stereochemical transformations (such as the Claisen rearrangement and Mitsunobu reaction) can remove or transfer the desired chirality thus simplifying the target.
|
|
A rearrangement occurs to form a high energy iron-oxygen species (which is generally thought to be an iron(IV)=O species) that performs the actual oxidation reaction.
|
|
In 2006 the museum was temporarily closed to the public when it embarked on a major refurbishment and rearrangement of the collections. It reopened on 15 May 2009.
|
|
The rearrangement drew upon the electronic models of Edward D. Hughes and Christopher Kelk Ingold, but also the non-electronic work of Rainer Ludwig Claisen and Ernst Tietze.
|
|
The changes revolve around chipset and processor design, in conjunction with a rearrangement of functions and controllers. The result is the first major change in many years of computing.
|
|
These rearrangements are performed in the presence of unsaturated compounds which undergo [2+2] cycloadditions with the in situ generated ketenes."Wolff Rearrangement." Organic-Chemistry. Organic Chemistry Portal, Web.
|
|
Radical clocks are used in reduction of alkyl halides with sodium naphthalenide, reaction of enones, the Wittig rearrangement, reductive elimination reactions of dialkylmercury compounds, dioxirane dihydroxylations, and electrophilic fluorinations.
|
|
1985, 50, 3604. (7)File:KetolScopeC.png Bridged ketols also undergo rearrangement, often stereospecifically.Creary, X.; Inocencio, P. A.; Underiner, T. L.; Kostromin, R. J. Org. Chem. 1985, 50, 1932. (8)File:KetolScopeB.
|
|
This enzyme participates in tyrosine metabolism. It employs one cofactor, 5-methylene-3,5-dihydroimidazol-4-one (MIO) which is formed autocatalytic rearrangement of the internal tripeptide Ala-Ser-Gly.
|
|
N-sulfonated amines can be obtained from the respective hydroxylamines and suitable sulfonation reagents. For example, Herderin et al. synthesized their secondary hydroxylamine (starting material in the rearrangement shown below) by subjecting the respective hydroxylamine to tosyl chloride and sodium hydroxide in acetonitrile. The Stieglitz rearrangement is especially reactive in the case of bridged bicyclic N-sulfonated amines as starting materials, where mild conditions are sufficient for an efficient reaction to take place.
|
|
The Johnson–Claisen rearrangement is the reaction of an allylic alcohol with an orthoester to yield a ester. Weak acids, such as propionic acid, have been used to catalyze this reaction. This rearrangement often requires high temperatures (100–200 °C) and can take anywhere from 10 to 120 hours to complete. However, microwave assisted heating in the presence of KSF-clay or propionic acid have demonstrated dramatic increases in reaction rate and yields.
|
|
The Demjanov rearrangement is a method to produce a 1-carbon ring enlargement in four, five or six membered rings. The resulting five, six, and seven-membered rings can then be used in further synthetic reactions. It has been shown that the Demjanov reaction is susceptible to regioselectivity. One example of this is a study conducted by D. Fattori looking at the regioselectivity of the Demjanov rearrangement in one-carbon enlargements of naked sugars.
|
|
Recombination can also occur due to errors in DNA replication that lead to genomic rearrangements. These events are often associated with pathology. However, genomic rearrangement is also thought to be a driving force in evolutionary development as it gives rise to novel gene combinations. Recombination hotspots may arise from the interaction of the following selective forces: the benefit of driving genetic diversity through genomic rearrangement coupled with selection acting to maintain favorable gene combinations.
|
|
Doering, although interacting with Humble Oil and Refining - and therefore also with Neureiter - as a consultant, in a 1963 publication stated the following : "Credit for discovery that vinylcyclopropane rearranges to cyclopentene is due to Overberger and Borchert, and Vogel et al., who appear to have developed several examples of the rearrangement independently." The development of further vinylcyclopropane rearrangement variants didn't take long as demonstrated by Atkinson & Rees in 1967, Lwowski in 1968.
|
|
Hence, in hindsight, the first observation of neocentromeres made by Andy Choo in 1997 was most likely an example of a Class II pericentric interstitial deletion, followed by a complex rearrangement. The neocentromere can either appear on the linear chromosome or on the ring chromosome, depending on which ever one lacks a centromere. For Class II, it is unclear when the rearrangement occurs. General postulations include the chromosome breaking twice, with the ends rejoining.
|
|
Competing reactions are the Sommelet-Hauser rearrangement and the Hofmann elimination. In one application a double-Stevens rearrangement expands a cyclophane ring.Macrocycle Ring Expansion by Double Stevens RearrangementKeisha K. Ellis-Holder, Brian P. Peppers, Andrei Yu. Kovalevsky, and Steven T. Diver Org. Lett.; 2006; 8(12) pp 2511 – 2514; (Letter) The ylide is prepared in situ by reaction of the diazo compound ethyl diazomalonate with a sulfide catalyzed by dirhodium tetraacetate in refluxing xylene.
|
|
He was the recipient of the Arthur C. Cope Award in 2003, and he was awarded the Tetrahedron Prize for Creativity in Organic Chemistry for 2008. Overman's research is focused on the development of new chemical reactions, particularly transition metal catalyzed reactions, and the application of those reactions toward the synthesis of natural products. Overman is most known for the Overman rearrangement, a Claisen rearrangement of allylic alcohols to give allylic trichloroacetamides.
|
|
The semipinacol rearrangement is a rearrangement reaction in organic chemistry involving a heterosubstituted alcohol of the type R1R2(HO)C–C(X)R3R4. The hetero substituent can be a halogen (Cl, Br, I), a tosylate, a mesylate or a thiol group. This reaction proceeds by removal of the leaving group X forming a carbocation as electron deficient center. One of the adjacent alkyl groups then migrates to the positive carbon in a 1,2-shift.
|
|
Other forms of solar activity frequently associated with coronal mass ejections are eruptive prominences, coronal dimming, coronal waves and Moreton waves, also called solar tsunami. Magnetic reconnection is responsible for CME and solar flares. Magnetic reconnection is the name given to the rearrangement of magnetic field lines when two oppositely directed magnetic fields are brought together. This rearrangement is accompanied with a sudden release of energy stored in the original oppositely directed fields.
|
|
This process of rearrangement can convert a very pathological function into one that is "nice" from the point of view of integration, and thus let such pathological functions be integrated.
|
|
Unsurprisingly, it was found that the ease of η5 to η3 haptotropic shift correlated to the strength of the Mn-X bond. General trend for haptotropic rearrangement assisted ligand substitution.
|
|
Susy Fuentes-Bazan, Pertti Uotila, Thomas Borsch: A novel phylogeny-based generic classification for Chenopodium sensu lato, and a tribal rearrangement of Chenopodioideae (Chenopodiaceae). In: Willdenowia 42, 2012, p. 18.
|
|
Susy Fuentes-Bazan, Pertti Uotila, Thomas Borsch: A novel phylogeny-based generic classification for Chenopodium sensu lato, and a tribal rearrangement of Chenopodioideae (Chenopodiaceae). In: Willdenowia 42, 2012, p. 17.
|
|
Paquette, L. A.; Montgomery, F. J.; Wang, T. Z. J. Org. Chem. 1995, 60, 7857. Similar stereoelectronic effects were observed in studies of the rearrangement of 17-hydroxy-20-ketosteroids.
|
|
Also, a t(14;18)(q22;21) bcl-2/IgH rearrangement has been described, as usually seen in follicular lymphoma.Immunologically, peripheral B-cells show more functional IgD+ positive CD27 cells than usual.
|
|
Treatment of the η1-coordinated phosphaalkyne complex trans- with an alkoxide resulted in desilylation, followed by subsequent rearrangement to the corresponding carbon-bound cyaphide complex. Cyaphide- alkynyl complexes are prepared similarly.
|
|
Wittig reagents are found to react as nucleophiles in SN2' substitution: :Wittig reagent in allylic rearrangement. 8% ene product not depicted The initial addition reaction is followed by an elimination reaction.
|
|
The earliest observation of a cycloheptadiene via the title rearrangement was made by Baeyer in his synthesis of eucarvone from carvone hydrobromide.Baeyer, A. Ber. 1894, 27, 810; ibid. 1898, 31, 2067.
|
|
Between that performance of the song and the release of the album, Kobametal felt the need for rearrangement of the music, such as the removal of death growls from the chorus.
|
|
The disease is also classified as one of numerous related and interrelated Epstein-Barr virus-associated lymphoproliferative diseases. EBV+ DLBCL, NOS is usually CD20 positive, and has clonal immunoglobulin gene rearrangement.
|
|
Radical 1,2-rearrangement The reaction proceeds through the triphenylmethoxyl radical A, a rearrangement to diphenylphenoxymethyl C and its dimerization. It is unclear to this day whether in this rearrangement the cyclohexadienyl radical intermediate B is a transition state or a reactive intermediate as it (or any other such species) has thus far eluded detection by ESR spectroscopy.Isomerization of Triphenylmethoxyl and 1,1-Diphenylethoxyl Radicals. Revised Assignment of the Electron-Spin Resonance Spectra of Purported Intermediates Formed during the Ceric Ammonium Nitrate Mediated Photooxidation of Aryl Carbinols K. U. Ingold, Manuel Smeu, and Gino A. DiLabio J. Org. Chem.; 2006; 71(26) pp 9906–9908; (Note) An example of a less common radical 1,2-shift can be found in the gas phase pyrolysis of certain polycyclic aromatic compounds.
|
|
In their synthesis of the antiviral drug oseltamivir, also known as Tamiflu, Ishikawa et al. used the Curtius rearrangement in one of the key steps in converting the acyl azide to the amide group in the target molecule. In this case, the isocyanate formed by the rearrangement is attacked by a carboxylic acid to form the amide. Subsequent reactions could all be carried out in the same reaction vessel to give the final product with 57% overall yield.
|
|
The migration of a divalent group, such as O, S, N–R, or C–R2, which is part of a three-membered ring in a bicyclic molecule, is commonly referred to as a walk rearrangement. This can be formally characterized according to the Woodward-Hofmann rules as being a (1, n) sigmatropic shift.Jensen, F. J. Am. Chem. Soc., 1989, 111, 13, 4643 – 4647. An example of such a rearrangement is the shift of substituents on tropilidenes (1,3,5-cycloheptatrienes).
|
|
A 1,2-rearrangement or 1,2-migration or 1,2-shift or Whitmore 1,2-shift is an organic reaction where a substituent moves from one atom to another atom in a chemical compound. In a 1,2 shift the movement involves two adjacent atoms but moves over larger distances are possible. In the example below the substituent R moves from carbon atom C2 to C3. 1,2-shift The rearrangement is intramolecular and the starting compound and reaction product are structural isomers.
|
|
Besides SN1 and SN2, other mechanisms are known, although they are less common. The SNi mechanism is observed in reactions of thionyl chloride with alcohols, and it is similar to SN1 except that the nucleophile is delivered from the same side as the leaving group. Nucleophilic substitutions can be accompanied by an allylic rearrangement as seen in reactions such as the Ferrier rearrangement. This type of mechanism is called an SN1' or SN2' reaction (depending on the kinetics).
|
|
429 State changes can include rotations and distortions of the object being transported as well as its translation in space.Postma, p. 4 As in rearrangement puzzles, no piece is ever lost or added to the board. In contrast to rearrangement puzzles, however, transport puzzles have all persons and objects follow certain routes given on the board; they cannot be lifted off the board and placed on faraway positions that have no visible connection to the from-position.
|
|
Host mucin cells have galactose and N-acetylgalactosamine which serve as the binding sites for these Gal/GalNac lectins. These lectins are a huge area of interest for scientists, as the association between these glycoproteins could potentially be a target for drug therapy. Once the trophozoites begin to aggregate, cyst differentiation is initiated by intracellular rearrangement which leads to cell rounding and cellular compaction. This rearrangement of the actin cytoskeleton seems to be crucial in differentiation to cysts.
|
|
The rate of addition to unsaturated carbon-carbon bonds is terminal alkyne > terminal alkene ≈ internal alkyne > disubstituted alkene Acyl complexes can be generated by insertion of CO into the C–Zr bond resulting from hydrozirconation. Upon alkene insertion into the zirconium hydride bond, the resulting zirconium alkyl undergoes facile rearrangement to the terminal alkyl and therefore only terminal acyl compounds can be synthesized in this way. The rearrangement most likely proceeds via β-hydride elimination followed by reinsertion.
|
|
The Westphalen–Lettré rearrangement is a classic organic reaction in organic chemistry describing a rearrangement reaction of cholestane-3β,5α,6β-triol diacetate with acetic anhydride and sulfuric acid. In this reaction one equivalent of water is lost, a double bond is formed at C10–C11 and importantly the methyl group at the C10 position migrates to the C5 position.Theodor Westphalen, Ber., 48, 1064 (1915) H. Lettré and I. Muller, Ber., 70, 1947 (1937) Rearranged Steroid Systems.
|
|
In mathematics, the symmetric decreasing rearrangement of a function is a function which is symmetric and decreasing, and whose level sets are of the same size as those of the original function.
|
|
Phosphetane and its derivatives are largely limited to academic interest. Exhaustive P-alkylation gives the corresponding phosphonium-salt (phosphetanium), these were used in the early examples of the Allen–Millar–Trippett rearrangement.
|
|
The highest reported yield, approximately 96%, is from the between phenol and propionyl chloride. The mechanism is likely to involve initial esterification to give phenyl propionate, which then undergoes a Fries rearrangement.
|
|
A study on the anionic oxy-Cope rearrangement carried out entirely in the gaseous phase reported that the rate enhancement stems not from solvent interactions, but from those within the structure itself.
|
|
General reaction for an aldol condensation between two carbonyl compounds. In the Meyer–Schuster rearrangement, the starting compound is a propargyl alcohol. Cyclic enones can be prepared via the Pauson–Khand reaction.
|
|
2-Naphthalenethiol is prepared from 2-naphthol by the Newman–Kwart rearrangement using the thiocarbamate. It undergoes lithiation at the 1 and 3-position. It can be used as a flavouring agent.
|
|
Specifically, for phosphoribosyl anthranilate isomerase, TkTrpF, from Thermococcus kodakaraensis. The active site for the Amadori rearrangement, was determined to be Cys8 (acting as the general base) and Asp135 (as the general acid).
|
|
Further treatment of 44 with potassium tert- butoxide furnished α-hydroxyketone 45 through a Lobry-de Bruyn-van Ekenstein Rearrangement. Substrate 45 was subsequently acylated to give α-acetoxyketone 46. Scheme 4.
|
|
Specification of endoderm depends on rearrangement of maternally deposited determinants, leading to nuclearization of Beta-catenin. Mesoderm is induced by signaling from the presumptive endoderm to cells that would otherwise become ectoderm.
|
|
The two chains are held in a high-energy conformation. When the local pH drops, the protein undergoes an energetically favorable conformational rearrangement that enables it to penetrate the host cell membrane.
|
|
Fe(III), Co(III), Ni(III), and Ni(IV) derivatives are known. In some cases, the oxidation induces rearrangement of the C2B9 cage to give complexes where the carbon centers are nonadjacent.
|
|
A molecular phylogenetic study published in 2013 found that Myrmeciza was polyphyletic. In the resulting rearrangement to create monotypic genera four species including the squamate antbird were moved to the resurrected genus Myrmoderus.
|
|
Additional evidence for this mechanism is provided by the finding that with a para tert-butyl substituent the reaction is retarded. 1,2-Wittig rearrangement competing mechanism The reaction is a formal dyotropic reaction.
|
|
1348) (Kharīdat al-ʿAjā'ib, "The Pearl of Wonders"), considered to be a derivative rearrangement of Yaqut,, p. 19, note 4. is an alternate source used by Lane who noted variant readings from it.
|
|
Pure cyclododecanone can then be converted into cyclododecanone oxime, which yields laurolactam after Beckmann rearrangement. Laurolactam is the precursor to several plastics, such as polyamide 12, which is also known as nylon 12.
|
|
In order to pass from the one-dimensional case to the higher-dimensional case, the spherical rearrangement is approximated by Steiner symmetrization for which the one- dimensional argument applies directly by Fubini's theorem.
|
|
In organic chemistry the Brook rearrangement refers to any [1,n] carbon to oxygen silyl migration. The rearrangement was first observed in the late 1950s by Canadian chemist Adrian Gibbs Brook (1924–2013), after which the reaction is named. These migrations can be promoted in a number of different ways, including thermally, photolytically or under basic/acidic conditions. In the forward direction, these silyl migrations produce silyl ethers as products which is driven by the stability of the oxygen-silicon bond.
|
|
Current research is exploring the possibilities of various directing groups to influence the selectivity of products in the Demjanov rearrangement, such as tin or silicon.This may lead to increased success with the Demjanov, as it would allow more control in the reaction and increase the desired product yield. The rearrangement is incredibly useful, but using it can sometimes prove ineffective by the difficulty of creating the preferred product. Thus if directing groups are possible, this would greatly improve the applicability of the Demjanov.
|
|
A Wagner–Meerwein rearrangement is a class of carbocation 1,2-rearrangement reactions in which a hydrogen, alkyl or aryl group migrates from one carbon to a neighboring carbon. They can be described as cationic [1,2]-sigmatropic rearrangements, proceeding suprafacially and with stereochemical retention. As such, a Wagner–Meerwein shift is a thermally allowed pericyclic process with the Woodward-Hoffmann symbol [ω0s \+ σ2s]. They are usually facile, and in many cases, they can take place at temperatures as low as –120 °C.
|
|
This is related to the rearrangement of the elements of in which each element is replaced by the corresponding . For example, the permutation (3,1,2) mentioned above is described by the function \alpha defined as: : \alpha(1) = 3, \quad \alpha(2) = 1, \quad \alpha(3) = 2. The collection of all permutations of a set form a group called the symmetric group of the set. The group operation is the composition (performing two given rearrangements in succession), which results in another rearrangement.
|
|
In general, the composition of two permutations is not commutative, that is, \pi\sigma eq \sigma\pi. As a bijection from a set to itself, a permutation is a function that performs a rearrangement of a set, and is not a rearrangement itself. An older and more elementary viewpoint is that permutations are the rearrangements themselves. To distinguish between these two, the identifiers active and passive are sometimes prefixed to the term permutation, whereas in older terminology substitutions and permutations are used.
|
|
Modified Wittig-Claisen tandem reactions Application of modified Wittig- Claisen tandem reactions for construction of 4-cyclooctenone structure. Application of modified Wittig-Claisen tandem reactions to the total synthesis of horsfiline. Modified Wittig-Claisen tandem reaction is a cascade reaction that combines Wittig reaction and Claisen rearrangement together. The Wittig reaction generates the allyl vinyl ether intermediate that further participates in a Claisen rearrangement to generate the final γ, δ-unsaturated ketone or aldehyde product (Figure "Modified Wittig-Claisen tandem reactions").
|
|
Its reaction mechanism centers around dissociation of the reactant with the positively charged organic residue R attacking the aniline ring in a Friedel–Crafts alkylation. In one study this rearrangement was applied to a 3-N(CH3)(C6H5)-2-oxindole:heating 1 in toluene at 80 °C gives 30% 2-o (ortho) and 37% 2-p (para) :Hofmann–Martius rearrangement of 3-N-Aryl-2-oxindoles The reaction is named after German chemists August Wilhelm von Hofmann and Carl Alexander von Martius.
|
|
This rearrangement reaction is named after its discoverer, Lars Skattebøl, Professor emeritus at the University of Oslo. It proceeds through a carbene reaction intermediate: Skattebøl rearrangement When the cyclopropane ring is fitted with a 2-vinyl group, a cyclopentadiene is formed through a so-called foiled carbene intermediate.Chemistry of gem- dihalocyclopropanes—VI A novel synthesis of cyclopentadienes and fulvenes L. Skattebøl Tetrahedron Volume 23, Issue 3 , 1967, Pages 1107-1117 .Leo A. Paquette and Mark L. McLaughlin Organic Syntheses, CV 8, 223 Link.
|
|
The reaction mechanism was confirmed by a reaction using 14C-labeled diazomethane. :Preparation of cyclobutanone from diazomethane and ketene via cyclopropanone Another synthesis of cyclobutanone involves lithium-catalyzed rearrangement of oxaspiropentane, which is formed by epoxidation of the easily accessible methylenecyclopropane. :Preparation of cyclobutanone by rearrangement Cyclobutanone can also be prepared in a two step procedure by dialkylation of 1,3-dithiane with 1-bromo-3-chloropropane followed by deprotection to the ketone with mercuric chloride (HgCl2) and cadmium carbonate (CdCO3).
|
|
The alpha-ketol rearrangement is an interconversion of a hydroxyl alpha to a carbonyl to the complementary carbonyl and hydroxyl groups, with migration of a substituent. It is mechanistically equivalent to the benzyllic acid rearrangement at the point after the nucleophile attacks the 1,2-dicarbonyl. This variation of the reaction has been known to occur in many substrates bearing the acyloin functional group. The picture below shows the ring expansion of a cyclopentane to a cyclohexane ring as an example reaction.
|
|
400px The final one-pot operation begins with a Curtius Rearrangement of acyl azide (7) to produce an isocyanate functional group at room temperature. The isocyanate derivative then reacts with acetic acid to yield the desired acetylamino moiety found in (1). This domino Curtius rearrangement and amide formation occurs in the absence of heat, which is extremely beneficial for reducing any possible hazard. The nitro moiety of (7) is reduced to the desired amine observed in (1) with Zn/HCl.
|
|
The residence has two timber doors, either side of an internal dividing wall which has been partly removed. The store is longer than the residence, and has a rear timber lean-to and a later corrugated iron addition. Internally, the residence has had a rearrangement of spaces, with walls removed and partitions added creating a bathroom, kitchen, bedroom and living space. The store has also had a rearrangement of spaces, with a streetfront display area, a bedroom and a storage area behind.
|
|
Overman's synthesis of strychnine represents a useful example of the preparation of precursors necessary for the aza-Cope/Mannich rearrangement, representing effective usage of an epoxide ring opening. The key steps of the synthesis of the rearrangement substrate leading to the starting materials necessary for the aza-Cope/Mannich reaction included a Stille reaction to piece together two precursors, an epoxidation of a double bond using tert- Butyl hydroperoxide, a Wittig reaction to convert the ketone to an alkene, and a cyclization step. Amine alkylation (not shown), transforms the molecule to the rearrangement substrate. Significantly, this molecule shows the enantiomeric precision of the aza-Cope/Mannich reaction, as a simple enantiomeric starting material dictates the final enantiomer: the enantiomer of strychnine was produced by using the enantiomer of the starting material.
|
|
Ernst Otto Beckmann (July 4, 1853 – July 12, 1923) was a German pharmacist and chemist who is remembered for his invention of the Beckmann differential thermometer and for his discovery of the Beckmann rearrangement.
|
|
Finally, the rearrangement of different orientation of carboplatin and CBDC leads to the formation of intramolecular hydrogen bond and a supramolecule of dicycloplatin with two O-H...O and N-H...O is created.
|
|
Discovered in 1912 by Rainer Ludwig Claisen, the Claisen rearrangement is the first recorded example of a [3,3]-sigmatropic rearrangement.Claisen, L.; Ber. 1912, 45, 3157. Claisen, L.; Tietze, E.; Chemische Berichte 1925, 58, 275.
|
|
The halogen dance concept can be extended from benzene derivatives to other aromatic systems as well, for instance furan and thiophene compounds. The halogen dance rearrangement of iodooxazoles was studied by the Stambuli Group.
|
|
Susy Fuentes-Bazan, Pertti Uotila, Thomas Borsch: A novel phylogeny-based generic classification for Chenopodium sensu lato, and a tribal rearrangement of Chenopodioideae (Chenopodiaceae). In: Willdenowia. Vol. 42, No. 1, 2012, p. 15-16.
|
|
The reaction is associated with the Maillard reaction in which the reagents are naturally occurring sugars and amino acids. One study demonstrated the possibility of Amadori rearrangement during interaction between oxidized dextran and gelatine.
|
|
The unlabeled T3P will react with the S7P to synthesize unlabeled products. The figure demonstrates the use of stable isotope labeling to discover the carbon atom rearrangement through reactions using position specific labeled compounds.
|
|
Nature, 13, 251–262. Accessed 9 April 2017. Utilization of chemical energy from such molecular bond rearrangement powers biological processes in every biological organism. Living organisms obtain energy from organic and inorganic materials; i.e.
|
|
On STS-74, the next Shuttle docking, Atlantis carried a docking module that was attached to Kristall. This allowed future Shuttle dockings to be carried out without the module rearrangement that had needed previously.
|
|
Sulfenate esters are intermediates in the Mislow-Evans rearrangement of allyl sulfoxides.Braverman, S., "Rearrangements involving sulfenic acids and their derivatives," in Sulfenic Acids and Derivatives, 1990, John Wiley & Sons. Sulfenamides have the formula RSNR′2.
|
|
The reduction of a carbonyl to a hydroxyl group and the loss of water then forms (+)maackiain, which undergoes stereochemical rearrangement and hydroxylation to form (+)6a-hydroxymaackiain. This molecule is then methylated to yield pisatin.
|
|
The conversion of GPP to alpha-terpinyl cation. The α-terpinyl cation (5) then undergoes a 1,2 hydride shift via a Wagner–Meerwein rearrangement, leading to the formation of the terpinen-4-yl cation (6).
|
|
In a binary tree, a node with two children cannot be deleted unambiguously. However, in certain binary trees (including binary search trees) these nodes can be deleted, though with a rearrangement of the tree structure.
|
|
The reaction mechanism for this rearrangement depends on the conditions employed to affect the rearrangement and the nature of the starting material. Anionic rearrangements are the most common Brook rearrangements observed, and their mechanisms can be broken into two general categories. The first category starts with proton abstraction of a nearby hydroxyl group by a base. This generates an alkoxide which then acts as a nucleophile and attacks the silicon atom in a nucleophilic displacement reaction, with the methylene group acting as the leaving group.
|
|
Before cutting, RuvC likely gains access to the Holliday junction by displacing one of the two RuvA tetramers covering the DNA there. Recombination results in either "splice" or "patch" products, depending on how RuvC cleaves the Holliday junction. Splice products are crossover products, in which there is a rearrangement of genetic material around the site of recombination. Patch products, on the other hand, are non-crossover products in which there is no such rearrangement and there is only a "patch" of hybrid DNA in the recombination product.
|
|
When isotopic labeling is used the products are often more varied and the distribution of the label more convoluted. In this case it is also important to explicitly predict the relative amounts of the label expected to appear at each position depending on the mechanism. center When the crossover experiment on the Claisen rearrangement is carried out only non-crossover products are observed. Based on this the mechanism is determined to be intramolecular, as depicted in the standard arrow-pushing mechanism for this rearrangement.
|
|
A cell containing a rearrangement of the bcr/abl chromosomal regions (upper left red and green chromosome). This rearrangement is associated with chronic myelogenous leukemia, and was detected using FISH. FISH chromosome in-situ hybridization allows the study cytogenetics in pre- and postnatal samples and is also widely used in cytogenetic testing for cancer. While cytogenetics is the study of chromosomes and their structure, cytogenetic testing involves the analysis of cells in the blood, tissue, bone marrow, or fluid to identify changes in chromosomes of an individual.
|
|
HRDetect was implemented to detect tumors with BRCA1/BRCA2 deficiency using the data from whole-genome sequencing. This model quantitatively aggregates six HRD-associated signatures into a single score called HRDetect to accurately classify breast cancers by their BRCA1 and BRCA2 status. The machine learning algorithm assigns weight values to these signatures prior to computing the final score. The six signatures, ranked by decreasing weight, include microhomology-mediated indels, the HRD index, base- substitution signature 3, rearrangement signature 3, rearrangement signature 5, and base- substitution signature 8.
|
|
If a couple has had one child with MDS, they can be offered prenatal screening in future pregnancies. This option is particularly important for the 20% of MDS families where one parent carries a balanced chromosome rearrangement. The risk of these couples having another child with MDS depends on the exact type of chromosomal rearrangement present and may be as high as 25–33%. For families in which both parents' chromosomes are normal, the risk of having another child with MDS is low (1% or less).
|
|
The reaction mechanism centers on the formation of a free radical pair with lithium migrating from the carbon atom to the oxygen atom. The R radical then recombines with the ketyl.Wittig Rearrangement of Lithiated Allyl Aryl Ethers: A Mechanistic Study Sven Strunk, Manfred Schlosser European Journal of Organic Chemistry Volume 2006, Issue 19 , pp. 4393–97 The 1,2-Wittig rearrangement reaction mechanism The alkyl group migrates in the order of thermodynamical stability methyl < primary alkyl < secondary alkyl < tertiary alkyl, this is in line with the radical mechanism.
|
|
Trypsinogen is activated by enteropeptidase (also known as enterokinase). Enteropeptidase is produced by the mucosa of duodenum and it cleaves the peptide bond of trypsinogen after residue 15, which is a lysine. The N-terminal peptide is discarded, and a slight rearrangement of the folded protein occurs. The newly formed N-terminal residue (residue 16) inserts into a cleft, where its α-amino group forms an ion pair with the aspartate near the active site serine, and results in the conformational rearrangement of other residues.
|
|
The benzidine rearrangement, which proceeds intramolecularly, is a classic mechanistic puzzle in organic chemistry. :400px The conversion is described as a [5,5]sigmatropic reaction.. :Benzidine rearrangement mechanism In terms of its physical properties, 4,4'-benzidine is poorly soluble in cold water but can be recrystallized from hot water, where it crystallises as the monohydrate. It is dibasic, the deprotonated species has Ka values of 9.3 × 10−10 and 5.6 × 10−11. Its solutions react with oxidizing agents to give deeply coloured quinone-related derivatives.
|
|
Multiplex RNA visualization in cells using ViewRNA FISH Assays A metaphase cell positive for the bcr/abl rearrangement (associated with chronic myelogenous leukemia) using FISH. The chromosomes can be seen in blue. The chromosome that is labeled with green and red spots (upper left) is the one where the rearrangement is present. Fluorescence in situ hybridization (FISH) is a molecular cytogenetic technique that uses fluorescent probes that bind to only those parts of a nucleic acid sequence with a high degree of sequence complementarity.
|
|
Carbocations are reactive intermediates in many organic reactions. This idea, first proposed by Julius Stieglitz in 1899, was further developed by Hans Meerwein in his 1922 study of the Wagner–Meerwein rearrangement. Carbocations were also found to be involved in the SN1 reaction, the E1 reaction, and in rearrangement reactions such as the Whitmore 1,2 shift. The chemical establishment was reluctant to accept the notion of a carbocation and for a long time the Journal of the American Chemical Society refused articles that mentioned them.
|
|
Resveratrol Photoisomerization: An Integrative Guided-Inquiry Experiment Elyse Bernard, Philip Britz-McKibbin, Nicholas Gernigon Vol. 84 No. 7 July 2007 Journal of Chemical Education 1159. :Resveratrol photoisomerization Thermal rearrangement of azulene to naphthalene has been observed.
|
|
Varying microbe strains and genomic content are caused by different forces, including three specific evolutionary events which have an impact on pathogen resistance and ability to cause disease, a: gene gain, gene loss, and genome rearrangement.
|
|
Northern part of Siheung City belonged to Incheon Metropolitan Prefecture (i.e. Incheon Dohobu, 인천도호부). In 1914, the two counties of Gwacheon and Ansan were annexed into Siheung County as part of rearrangement policy of administrative districts.
|
|
The most significant subsequent restoration commenced in 1979 under Bernard Feilden and Simpson & Brown: this included the levelling of the floor and the rearrangement of the interior around a central communion table.Marshall 2009, pp. 171-172.
|
|
4,4'-Dihydroxybenzophenone is prepared by the rearrangement of p-hydroxyphenylbenzoate: :HOC6H4CO2C6H5 → (HOC6H4)2CO Alternatively, p-hydroxybenzoic acid can be converted to p-acetoxybenzoyl chloride. This acid chloride reacts with phenol to give, after deacetylation, 4,4'-dihydroxybenzophenone.
|
|
Nitrilium ions are believed to be intermediates in the hydrolysis of nitriles, the Beckmann rearrangement, the Friedel-Crafts cyclization of amines to isoquinolines, the Schmidt reaction with ketones, and the Ugi, Ritter, Pinner and Passerini reactions.
|
|
In 2014, it was found that the genome of the plastid, found in the iris, unlike orchid genomes, has little gene loss and rearrangement and is likely to be similar to other genomes from Asparagales order.
|
|
In comparison to the original 1997 usage of the term, this version of guerrilla librarianship involves the removal or rearrangement of books by the general public regarding bookstores as opposed to librarians in public library settings.
|
|
The reaction is closely related to the Curtius rearrangement except that in this reaction the acyl azide is produced by reaction of the carboxylic acid with hydrazoic acid via the protonated carboxylic acid, in a process akin to a Fischer esterification. An alternative, involving the formation of an acylium ion, becomes more important when the reaction takes place in concentrated acid (>90% sulfuric acid). (In the Curtius rearrangement, sodium azide and an acyl chloride are combined to quantitatively generate the acyl azide intermediate, and the rest of the reaction takes place under neutral conditions.) The carboxylic acid Schmidt reaction starts with acylium ion 1 obtained from protonation and loss of water. Reaction with hydrazoic acid forms the protonated azido ketone 2, which goes through a rearrangement reaction with the alkyl group R, migrating over the C-N bond with expulsion of nitrogen.
|
|
A molecular phylogenetic study published in 2013 found that Myrmeciza, as then defined, was polyphyletic. In the resulting rearrangement to create monophyletic genera four species including the ferruginous-backed antbird were moved to the resurrected genus Myrmoderus.
|
|
A molecular phylogenetic study published in 2013 found that Myrmeciza, as then defined, was polyphyletic. In the resulting rearrangement to create monotypic genera four species including the white-bibbed antbird were moved to the resurrected genus Myrmoderus.
|
|
In addition, films can break under disjoining pressure, These effects can lead to rearrangement of the foam structure at scales larger than the bubbles, which may be individual (T1 process) or collective (even of the "avalanche" type).
|
|
Glibornuride synthesis: See also: ; eidem, (to Hoffmann-La Roche). Gliburnide is an endo-endo derivative made from camphor-3-carboxamode by borohydride reduction (exo approach), followed by Hofmann rearrangement to carbamate, followed by displacement with sodium tosylamide.
|
|
Acid-labile substrates are less likely to undergo rearrangement and elimination since DAST is less prone to contamination with acids. Reaction temperatures are milder as well – alcohols typically react at −78 °C and ketones around 0 °C.
|
|
Geheimrat Julius Wilhelm Theodor Curtius (27 May 1857 - 8 February 1928) was professor of Chemistry at Heidelberg University and elsewhere. He published the Curtius rearrangement in 1890/1894 and also discovered diazoacetic acid, hydrazine and hydrazoic acid.
|
|
It was believed that the Curtius rearrangement was a two-step processes, with the loss of nitrogen gas forming an acyl nitrene, followed by migration of the R-group to give the isocyanate. However, recent research has indicated that the thermal decomposition is a concerted process, with both steps happening together, due to the absence of any nitrene insertion or addition byproducts observed or isolated in the reaction. Thermodynamic calculations also support a concerted mechanism. Mechanism of the Curtius rearrangement The migration occurs with full retention of configuration at the R-group.
|
|
Mechanism of the photochemical Curtius rearrangement Photochemical decomposition of the acyl azide is also possible. However, photochemical rearrangement is not concerted and instead occurs by a nitrene intermediate, formed by the cleavage of the weak N–N bond and the loss of nitrogen gas. The highly reactive nitrene can undergo a variety of nitrene reactions, such as nitrene insertion and addition, giving unwanted side products. In the example below, the nitrene intermediate inserts into one of the C–H bonds of the cyclohexane solvent to form N-cyclohexylbenzamide as a side product.
|
|
In one variation called the Darapsky degradation,August Darapsky (1936) "Darstellung von α-Aminosäuren aus Alkyl-cyanessigsäuren" (Preparation of α-amino acids from alkyl cyanoacetic acids), Journal für Praktische Chemie, 146 : 250-267. or Darapsky synthesis, a Curtius rearrangement takes place as one of the steps in the conversion of an α-cyanoester to an amino acid. Hydrazine is used to convert the ester to an acylhydrazine, which is reacted with nitrous acid to give the acyl azide. Heating the azide in ethanol yields the ethyl carbamate via the Curtius rearrangement.
|
|
The photochemical Curtius-like migration and rearrangement of a phosphinic azide forms a metaphosphonimidate in what is also known as the Harger reaction (named after Dr Martin Harger from University of Leicester). This is followed by hydrolysis, in the example below with methanol, to give a phosphonamidate. Scheme of the Harger reaction Unlike the Curtius rearrangement, there is a choice of R-groups on the phosphinic azide which can migrate. Harger has found that the alkyl groups migrate preferentially to aryl groups, and this preference increases in the order methyl < primary < secondary < tertiary.
|
|
The Curtius rearrangement is tolerant of a large variety of functional groups, and has significant synthetic utility, as many different groups can be incorporated depending on the choice of nucleophile used to attack the isocyanate. For example, when carried out in the presence of tert-butanol, the reaction generates Boc-protected amines, useful intermediates in organic synthesis. Likewise, when the Curtius reaction is performed in the presence of benzyl alcohol, Cbz-protected amines are formed. The Curtius rearrangement is used in the syntheses of the drugs tranylcypromine, candesartan, bromadol, terguride, benzydamine, gabapentin, igmesine and tecadenoson.
|
|
The mechanism of the Pummerer rearrangement begins with the acylation of the sulfoxide (resonance structures 1 and 2) by acetic anhydride to give 3, with acetate as byproduct. The acetate then acts as a catalyst to induce an elimination reaction to produce the cationic-thial structure 4, with acetic acid as byproduct. Finally, acetate attacks the thial to give the final product 5. The mechanism of the Pummerer rearrangement The activated thial electrophile can be trapped by various intramolecular and intermolecular nucleophiles to form carbon–carbon bonds and carbon–heteroatom bonds.
|
|
From studies and predictions such as Dreyer and Bennett's, it shows that the light chains and heavy chains are encoded by separate multigene families on different chromosomes. They are referred to as gene segments and are separated by non-coding regions. The rearrangement and organization of these gene segments during the maturation of B cells produce functional proteins. The entire process of rearrangement and organization of these gene segments is the vital source where our body immune system gets its capabilities to recognize and respond to variety of antigens.
|
|
It is understood that rearrangement occurs between specific sites on the DNA called recombination signal sequences (RSSs). The signal sequences are composed of a conserved palindromic heptamer and a conserved AT- rich nonamer. These signal sequences are separated by non- conserved spacers of 12 or 23 base pairs called one-turn and two-turn respectively. They are within the lambda chain, k-chain and The processes of rearrangement in these regions are catalyzed by two recombination-activating genes: RAG-1 and RAG-2 and other enzymes and proteins.
|
|
The Rearrangement hotspot system (Rhs) exists in both Gram-negative and Gram-positive bacteria. Similar to CdiA, these systems consists of big proteins with a conserved N-terminal domain and a variable C-terminal toxin domain requiring a cognate immunity protein. Many Rhs systems contain PAAR-domains (Proline-Alanine- Alanine-Arginine) which can interact with the VgrG of the T6SS apparatus making it required for Rhs secretion. The name Rearrangement hotspots comes from the discovery when the system was first identified as elements on the E. coli chromosome that were continuously rearranging.
|
|
They found that the reaction temperature could be lowered drastically when the cyclopropane ring contained a dithiane group. Even though the dithiane-substituted vinylcyclopropane substrates required two synthetic steps starting from the corresponding 1,3-dienes the method proved itself successful for the synthesis of a variety of substituted cyclopentenes. The immediate rearrangement products could be easily converted to the corresponding cyclopentenones. Corey Only a year later Simpson and co-workers demonstrated that also simple methoxy-substituted vinylcyclopropanes show significantly faster reaction rates allowing the rearrangement to take place at 220 °C.
|
|
The Meyer–Schuster rearrangement has been used in a variety of applications, from the conversion of ω-alkynyl-ω-carbinol lactams into enamides using catalytic PTSAChihab- Eddine, A.; Daich, A.; Jilale, A.; Decroix, B. J. Heterocycl. Chem. 2000, 37, 1543–1548.() to the synthesis of α,β-unsaturated thioesters from γ-sulfur substituted propargyl alcoholsYoshimatsu, M.; Naito, M.; Kawahigashi, M.; Shimizu, H.; Kataoka, T. J. Org. Chem. 1995, 60, 4798–4802.() to the rearrangement of 3-alkynyl-3-hydroxyl-1H-isoindoles in mildly acidic conditions to give the α,β-unsaturated carbonyl compounds.
|
|
Mechanistic details were also discussed, however further investigations in collaboration with the Houk group revealed an unusual and unexpected mechanism based on computational studies. The new mechanism involves formation of a vinyl ketene. Rearrangement of Zincke aldehydes to Z-unsaturated amides New ketene-based mechanism for rearrangement of Zincke aldehydes The Vanderwal group has also reported the synthesis of 4-stannyldienals from Zincke aldehydes by addition of tributylstannyl anion and quenching with acetyl chloride. The products are useful substrates for Stille cross-coupling reactions to give interesting polyene structures.
|
|
Photodegradation is BPA's main method of natural weathering in the environment, via the Photo Fries rearrangement. Experimentally, BPA has been shown to photodegrade in reactions catalyzed by zinc oxide, titanium dioxide, and tin dioxide, as methods of water decontamination procedures. The Photo Fries degradation is a complex rearrangement of the aromatic carbonate backbone of BPA into phenyl salicylate and dihydroxybenzophenone derivatives before the energized ring releases carbon dioxide. In aqueous solution, BPA shows UV absorption of wavelengths between 250 nm and 360 nm, and the Photo Fries degradation occurs at wavelengths less than 300 nm.
|
|
The Irvine graduate program was small and thus in his early work Overman frequently performed experiments himself, including his initial discovery of the Overman rearrangement. Palladium emerged as the metal of choice for this reaction, and this led to a long-term interest in palladium catalysis, including the palladium(II)-catalyzed Cope rearrangement, and later work on intramolecular cascading Heck reactions. Overman has performed many total syntheses of natural products, beginning with (±)-pumiliotoxin C (with Peter Jessup) in the late seventies. This interest was spurred on by a 1977 sabbatical visit by Samuel J. Danishefsky.
|
|
Oxaziridines have been found to undergo rearrangement reactions via a radical mechanism when irradiated with UV light or in the presence of a single electron transfer reagent such as CuI. spirocylic oxaziridines undergo ring expansions to the corresponding lactam. The migrating substituent is determined by a stereoelectronic effect where the group trans to the lone pair on the nitrogen will always be the predominant migration product. In light of this effect, it is possible to take advantage of the chiral nitrogen due to high inversion barrier to direct the rearrangement.
|
|
This phenomenon is demonstrated by observed selectivities in the rearrangements below. In the rearrangement on the left the thermodynamically unfavorable product is observed exclusively, while in the reaction on the right the product derived from the less stable radical intermediate is favored. Evidence for selectivity based on nitrogen lone pair orientation. Aubé takes advantage of this rearrangement as the key step in his synthesis of (+)-yohimbine, a natural medicine classified by the NIH as possibly effective in the treatment of erectile dysfunction and the sexual problems caused by selective serotonin reuptake inhibitors.
|
|
Laundy served as the Assistant Minister for Multicultural Affairs between February and July 2016 following a rearrangement in the First Turnbull Ministry and served as the Assistant Minister for Industry, Innovation and Science between July 2016 and December 2017 in the Second Turnbull Ministry. Following a subsequent rearrangement of the ministry in December 2017, he was appointed as the Minister for Small and Family Business, the Workplace and Deregulation. He resigned from the position in August 2018 following the election of Scott Morrison in a Liberal Party Leadership spill.
|
|
The major application of the Gabriel–Colman rearrangement is in the formation of isoquinolines, due to the relatively high yield of the desired products. Therefore, studies in which either the product or an intermediate is an isoquinoline, the Gabriel–Colman rearrangement can be utilized. This reaction has been utilized in the production of intermediates for the synthesis of potential anti-inflammatory agents. It has also been used in the study of phthalimide and saccharin derivatives as mechanism based inhibitors for three enzymes; the human leukocyte elastase, cathepsin G and proteinase 3.
|
|
This match – originally scheduled to be held during Round 12, on 8 January 2016 – was postponed due to a European Rugby Champions Cup fixture rearrangement that occurred as a result of the Paris terrorist attacks in November 2015.
|
|
However, its scope is limited. The Demjanov rearrangement is only best suited for expanding four, five, and six member aminomethylcycloalkanes. Moreover, alkenes and un-expanded cycloalcohols form as by-products. Yields diminish as the starting cycloalkane becomes larger.
|
|
When treated with a Lewis acid, oxime methanesulfonates undergo facile Beckmann rearrangement. Methanesulfonates are occasionally used as a protecting group for alcohols. They are stable to acidic conditions and is cleaved back to the alcohol using sodium amalgam.
|
|
Structural CIN is different in that rather than whole chromosomes, fragments of chromosomes may be duplicated or deleted. The rearrangement of parts of chromosomes (translocations) and amplifications or deletions within a chromosome may also occur in structural CIN.
|
|
These strands then undergo a process called lumenization, the spontaneous rearrangement of endothelial cells from a solid cord into a hollow tube.Forgacs, G. and Newman, S.A. (2005). Biological Physics of the Developing Embryo. Cambridge, UK: Cambridge University Press.
|
|
Translocations that always involve rearrangement of the RARA gene are a cardinal feature of acute promyelocytic leukemia (APL; MIM 612376). The most frequent translocation is t(15,17)(q21;q22), which fuses the RARA gene with the PML gene.
|
|
2-Naphthol reacts to form BINOL, a C2-symmetric ligand popularized for use in asymmetric catalysis. Coupling of beta-naphthol using CuCl2 2-Naphthol converts to 2-naphthalenethiol via reaction with dimethylthiocarbamoyl chloride via the Newman-Kwart rearrangement.
|
|
Compared with the derivation in standard usage, this alternate derivation avoids fractions and squared fractions until the last step and hence does not require a rearrangement after step 3 to obtain a common denominator in the right side.
|
|
Early in 2007 Mast and Thiele initiated a rearrangement of Banksia by transferring Dryandra into it, and publishing B. subg. Spathulatae for the species having spoon-shaped cotyledons. The members of B. ser. Quercinae fall within B. subg.
|
|
Cyclopentene is used in analysing the mechanisms of organic reactions. It can be obtained from vinylcyclopropane in the vinylcyclopropane-cyclopentene rearrangement. The polymerization of cyclopentene by Ziegler-Natta catalysts yields 1,3-linkages, not the more typical 1,2-linked polymer.
|
|
Basing it on the original melody, Franz Liszt has composed the Gaudeamus igitur—Paraphrase and later (1870) the Gaudeamus igitur—Humoreske. Modern version is rearrangement for male chorus with piano accompaniment, by Peter Tchaikovsky (1874) (TH 187 ; ČW 413).
|
|
Raynald is generally credited with compiling the Instituta generalis capituli apud Cistercium, the earliest collection of the decisions of the Cistercian general chapter, and may also be credited with the shorter Capitula, a summary and rearrangement of the Instituta.
|
|
Dimethylthiocarbamoyl chloride is an organosulfur compound with the formula (CH3)2NC(S)Cl. A yellow solid, it is often encountered as a yellow syrup. It is a key reagent in the synthesis of arylthiols via the Newman-Kwart rearrangement.
|
|
Robert John "Robin" Ferrier FRSNZ, FNZIC, (7 August 1932 – 11 July 2013) was an organic chemist who discovered two chemical reactions, the Ferrier rearrangement and the Ferrier carbocyclization. Originally from Edinburgh, he moved to Wellington, New Zealand, in 1970.
|
|
The construction of the Keenleyside Dam north of Castlegar in 1968 and the resulting rise of the lake level caused the rearrangement of the village and its waterfront.Wilson, J.W. (1973). People in the Way. Toronto, ON: University of Toronto Press.
|
|
Tiffeneau's discovery enlarged the synthetic scope of the Demjanov rearrangement as now seven and eight carbon rings could be enlarged. Since the resulting cycloketone could be easily converted to a cycloaminoalcohol again, this new method quickly became popular among organic chemists.
|
|
The structure of a typical acylsilane. Acylsilanes are a group of chemical compounds sharing a common functional group with the general structure R(CO)-SiR3. Acylsilanes are starting compounds in the Brook rearrangement with vinyl lithium compounds to silyl enol ethers.
|
|
In mathematical analysis, the Pólya–Szegő inequality (or Szegő inequality) states that the Sobolev energy of a function in a Sobolev space does not increase under symmetric decreasing rearrangement. The inequality is named after the mathematicians George Pólya and Gábor Szegő.
|
|
According to a local custom, Seleucus was always offered an extra cup of wine during dinner time. His title during this period was Seleucus Soter ("saviour"). When Seleucus left for Europe, the organizational rearrangement of Asia Minor had not been completed.
|
|
It can be synthesized by nitration of benzamide followed by the Hofmann rearrangement of the 3-nitrobenzamide previously formed. It consist in treating the 3-nitrobenzamide with sodium hypobromite or sodium hypochlorite to transform the amide group into an amine.
|
|
Pre-TCR-mediated feedback on TCRbeta rearrangement as essential mechanism for TCRbeta allelic exclusion. Lack of TCRalpha allelic exclusion. # Bruno, L., Kirberg, J. and von Boehmer, H.: On the cellular basis of immunological T cell memory. Immunity 2,37-43 (1995).
|
|
ABCG2 can export anthrocycline anticancer drugs, as well as topotecan, mitoxantrone, or doxorubicin as substrates. Chromosomal translocations have been found to cause the ABCG2 amplification or rearrangement found in resistant cell lines. The normal function of ABCG2 is not known.
|
|
Various types of cancers can also be born from mutations of the tandem repeats in the ribosomal DNA. Cell lines can become malignant from either a rearrangement of the tandem repeats, or an expansion of the repeats in the rDNA.
|
|
Recently, γ-butyrobetaine hydroxylase, an enzyme that is involved in the human carnitine biosynthesis pathway, was found to catalyze a C-C bond formation reaction in a fashion analogous to a Stevens type rearrangement. The substrate for the reaction is meldonium.
|
|
Sergey Semyonovich Namyotkin (; - 5 August 1950) was a Russian chemist, a prominent researcher in terpene chemistry and rearrangement of camphenes.L. A Kalashnikova (1990) "Sergei Semenovich Nametkin: 1876-1950" (Materialy k biobibliografii uchenykh SSSR. Seriia khimicheskikh nauk / Akademiia nauk SSSR). Nauka.
|
|
Santonic acid is an organic compound containing both carboxylic acid and ketone functionality. It was synthesized from santonin by base-mediated hydrolysis of a lactone followed by a multistep rearrangement process by R. B. Woodward.Reusch, William (1999). "Base-catalyzed rearrangements ".
|
|
In the above example, actin cytoskeleton rearrangement is required for proliferation (cytokinesis during mitosis). IQGAP1 helps cells both listen to and act on signals, playing an integral role in connecting the dots between signals for proliferation and the actual cellular response.
|
|
Taxodone is a naturally occurring diterpenoid found in Taxodium distichum (Bald Cypress), Rosmarinus officinalis (Rosemary), several Salvia species and other plants, along with its oxidized rearrangement product, taxodione. Taxodone and taxodione exhibit anticancer, antibacterial, antioxidant, antifungal, insecticide, and antifeedant activities.
|
|
The town was founded on September 28, 1850, by pioneer Santiago Santamaría. It was established as municipality on 1851. During a territorial rearrangement on the country on 1908, Jericó became the capital of the homonymous department until 1911.Marca Colombia.
|
|
This can be avoided by using a chiral auxiliary substituent on the amine. Reactions tethered to rings cannot undergo these bond rotations. Bond rotation leading to racemic product. The aza-Cope rearrangement proceeding the bond rotation is omitted for clarity.
|
|
Benzilic acid can be prepared by heating mixture of benzil, ethanol and potassium hydroxide. Another preparation, performed by Liebig in 1838, is the dimerization of benzaldehyde, to benzil, which is transformed to the product by the benzilic acid rearrangement reaction.
|
|
That is, the rearrangement reveals a state variable filter structure. By using different states as outputs, different kinds of filters can be produced. In more general state variable filter examples, additional filter orders are possible with more integrators (i.e., more states).
|
|
D. H. R.; P. T. Gillam, P. T., 1960, J. Chem. Soc., 4596-4599. In this rearrangement, the C-3 carbonyl group moves to C-2, the C-4 methyl moves to C-1, and the C-10 carbon inverts.
|
|
Banksia, being most closely related to B. ser. Ochraceae and B. ser. Prostratae. Early in 2007 Mast and Thiele initiated a rearrangement of Banksia by transferring Dryandra into it, and publishing B. subg. Spathulatae for the species having spoon-shaped cotyledons.
|
|
Molecular Plant-Microbe Interactions (2011) 24: 938-947. 10\. Dynamic rearrangement of F-actin organization triggered by host-specific plant signal is linked to morphogenesis of Aphanomyces cochlioides zoospores. M. T. Islam. Cell Mot. Cytoskel. (2008) 65: 553-562. 11\.
|
|
To diketone 23 was added sodium acetylide (bringing in carbon atoms 22 and 23) to give alkyne 24. This compound was reduced to the allyl alcohol 25 using the Lindlar catalyst and lithium aluminium hydride removed the remaining ketone group in 26. An allylic rearrangement to alcohol 27 (isostrychnine) was brought about by hydrogen bromide in acetic acid followed by hydrolysis with sulfuric acid. In the final step to (−)-strychnine 28 treatment of 27 with ethanolic potassium hydroxide caused rearrangement of the C12-13 double bond and ring closure in a conjugate addition by the hydroxyl anion.
|
|
These include tosyl chloride, thionyl chloride, phosphorus pentachloride, phosphorus pentoxide, triethylamine, sodium hydroxide, trimethylsilyl iodide among others. The Beckmann fragmentation is another reaction that often competes with the rearrangement, though careful selection of promoting reagent and solvent conditions can favor the formation of one over the other, sometimes giving almost exclusively one product. The rearrangement occurs stereospecifically for ketoximes and N-chloro/N-fluoro imines, with the migrating group being anti-periplanar to the leaving group on the nitrogen. Certain conditions have been known to racemize the oxime geometry, leading to the formation of both regioisomers.
|
|
The most common reaction mechanism of the Beckmann rearrangement consists generally of an alkyl migration anti-periplanar to the expulsion of a leaving group to form a nitrilium ion. This is followed by solvolysis to an imidate and then tautomerization to the amide: :Beckmann rearrangement mechanism This nitrilium ion has been known to be intercepted by other nucleophiles, including the leaving group from the oxime. 500x500px Presumably after the phenyl group migrates and expels the cyanate, it then attacks the nitrillium ion formed. In carbon tetrachloride the isocyanate can be isolated, whereas in ethanol the urethane is formed after solvolysis of the isocyanate.
|
|
A sigmatropic reaction in organic chemistry is a pericyclic reaction wherein the net result is one σ-bond is changed to another σ-bond in an uncatalyzed intramolecular reaction.Carey, F.A. and R.J. Sundberg. Advanced Organic Chemistry Part A The name sigmatropic is the result of a compounding of the long-established sigma designation from single carbon–carbon bonds and the Greek word tropos, meaning turn. In this type of rearrangement reaction, a substituent moves from one part of a π-bonded system to another part in an intramolecular reaction with simultaneous rearrangement of the π system.
|
|
The harness of the reaction conditions needed for the rearrangement differed based upon the reactivity of the substrates. Piancatelli observed that the more reactive substrates such as 5-methyl-2-furylcarbinols can undergo the rearrangement with much milder conditions in order to avoid any possible side products. Lewis acids were discovered to help drive the reaction to completion as long as there was an equimolar ratio, whereas alkyl groups on the hydroxy-bearing carbon leave the starting material more stable and cause longer reaction times and lower yields with the formation of side products due to the increased reactivity of those carbocations.
|
|
Heteroatom additions to rings can occur through ring expansions if not they are not done through de-novo ring synthesis. These introductions are primarily ring expansions because they often take place through migration/insertion pathways similar to those mentioned above for carbon. Examples include high impact applications of the Beckmann rearrangement (for introduction of nitrogen into codeine) and the Baeyer-Villiger oxidation (introduction of oxygen to cage-annulated ethers) in synthesis. Both occur with the expulsion of a leaving group as the alkyl group migrates onto the exocyclic heteroatom, which is strikingly similar to the pinacol type rearrangement.
|
|
A tumor-specific LACTB2-NCOA2 fusion originating from intra-chromosomal rearrangement of chromosome 8 has been identified at both DNA and RNA levels. Unlike conventional oncogenic chimeric proteins, the fusion product lacks functional domain from respective genes, indicative of an amorphic rearrangement. This chimeric LACTB2-NCOA2 transcript was detected in 6 out of 99 (6.1%) colorectal cancer (CRC) cases, where NCOA2 was significantly downregulated. Enforced expression of wild-type NCOA2 but not the LACTB2-NCOA2 fusion protein impaired the pro-tumorigenic phenotypes of CRC cells, whereas knockdown of endogenous NCOA2 in normal colonocytes had opposite effects.
|
|
He worked first with Hermann Emil Fischer on the field of organic chemistry, but changed to electrochemistry after his work with Wilhelm Ostwald. He is known for the discovery of an electrosynthetic rearrangement reaction of various alkylated ethyl acetoacetates to form hydrocarbons, now called the Tafel rearrangement, and the Tafel equation, which relates the rate of an electrochemical reaction to the overpotential. He is also credited for the discovery of the catalytic mechanism of hydrogen evolution (the Tafel mechanism). Tafel retired aged 48 due to ill health, but continued to write book reviews until his death.
|
|
Overman and coworkers recognized that the cationic 2-aza-Cope rearrangement could potentially be synthetically powerful if an appropriate thermodynamic sink could be introduced. Their logic was to incorporate a nucleophilic substituent into the starting material, namely an alcohol group, which acts only after rearrangement, converted into an enol primed to attack the iminium ion. This first report of the reaction was a reaction between aldehydes and 2-alkoxy-3-butenamines, which formed an amino alcohol whose aza-Cope/Mannich reaction product was an acyl-substituted pyrrolidine ring. This simple procedure only involved mild heating for several hours.
|
|
Stepwise Mechanisms in the Oxy-Cope Rearrangement Jerome A. Berson and Maitland Jones pp 5017 – 5018; J. Am. Chem. Soc. 1964; Oxy-Cope rearrangement In its original form, the reaction needs very high temperatures to proceed at a reasonable rate. However, in 1975, David A. Evans and A. M. Golob showed that deprotonation of oxy-Cope substrates with strong base to form the corresponding potassium alkoxide resulted in rate accelerations of 1010 to 1017 relative to the reaction conducted under neutral conditions. This allows the reaction to be conducted at room temperature or even 0 °C.
|
|
Nonetheless, as gene rearrangement events involving ROS1 have been described in lung and other cancers, and since such tumors have been found to be remarkably responsive to small molecule tyrosine kinase inhibitors, interest in identifying ROS1 rearrangements as a therapeutic target in cancer has been increasing. Recently, the small molecule tyrosine kinase inhibitor, crizotinib, was approved for the treatment of patients with metastatic NSCLC whose tumors are ROS1 -positive. Gene rearrangements involving the ROS1 gene were first detected in glioblastoma tumors and cell lines. In 2007 a ROS1 rearrangement was identified in a cell line derived from a lung adenocarcinoma patient.
|
|
Following the 2013 federal election that resulted in the formation of the Abbott Ministry, Ryan was appointed as the Parliamentary Secretary to the Minister for Education; later expanded as the Parliamentary Secretary to the Minister for Education and Training. Ryan served as the Minister for Vocational Education and Skills following a rearrangement in the First Turnbull Ministry, between February and July 2016. Ryan was appointed the Special Minister for State in the first arrangement of the Second Turnbull ministry and gained additional responsibilities as the Minister Assisting the Prime Minister for Cabinet in a subsequent rearrangement.
|
|
The second category of anionic brook rearrangements involves nucleophilic attack at an sp2 hybridized center to generate an oxy-anion two atoms removed from the silicon atom. This can then undergoes intramolecular attack by the oxy-anion to yield the silyl ether, but the final fate of the carbanion often depends on the substrate in question. For example, attempting to perform a Wittig reaction on acylsilane results in the formation of a silyl enol ether instead of the expected alkene, due to elimination by the carbanion instead of protonation as seen above. 683x683px The Brook rearrangement has been shown to occur with retention of configuration at the silicon center as demonstrated in the following Walden cycle: The Brook rearrangement Walden cycle All steps in this cycle were known to proceed with retention of configuration except for attack of the lithium reagent (which proceeded by inversion) and the Brook Rearrangement, which was being investigated.
|
|
Oseltamivir has a large hydrophobic side chain and the NA must undergo rearrangement to form a pocket for drug binding by rotating aminoacid E276 and bond with R224. Mutations like H274Y, R292K and N294S that affect this forming could reduce the inhibitor's efficiency.
|
|
Either approach converts the dihalogenated carbon to a carbene or carbenoid-like structure. The resulting cyclopropylcarbene rearranges to form the allene product. The electronic nature of the carbene intermediate is not entirely understood. Several different mechanisms for its electrocyclic rearrangement have been studied.
|
|
Shiau TP, Houchin A, Nair S, Xu P, Low E, Najafi RR, Jain R. "Stieglitz rearrangement of N,N-dichloro-beta,beta-disubstituted taurines under mild aqueous conditions." Bioorg Med Chem Lett. 2009 Feb 15;19(4):1110-4. doi: 10.1016/j.bmcl.2008.12.109.
|
|
The reaction, formally a rearrangement, ranks under the elimination reactions as already observed by the original authors. Not only alkoxides but any leaving group capable of carrying a negative charge will do for instance nitrate esters R–C(R)(H)–O–NO2.
|
|
Majewska H, Skálová A, Stodulski D, Klimková A, Steiner P, Stankiewicz C, Biernat W. "Mammary analogue secretory carcinoma of salivary glands: a new entity associated with ETV6 gene rearrangement." Virchows Arch. 2015 Mar;466(3):245-54. doi: 10.1007/s00428-014-1701-8.
|
|
Isobutyraldehyde is produced industrially by the hydroformylation of propene. Several million tons are produced annually.Boy Cornils, Richard W. Fischer, Christian Kohlpaintner "Butanals" in Ullmann's Encyclopedia of Industrial Chemistry, 2000, Wiley-VCH, Weinheim. Strong mineral acids catalyse the rearrangement of methallyl alcohol to isobutyraldehyde.
|
|
After a rearrangement the intermediate compound (5) is built. This reacts with a hydroxydion of the caustic potash 6. In the next step the molecule dissociates into two pieces 7 and 8. (8) is protonated and builds the acetic acid derivative (9).
|
|
In addition to the ordinary thermal phenyl ester reaction a photochemical variant is possible. The photo-Fries rearrangement can likewise give [1,3] and [1,5] products. that involves a radical reaction mechanism. This reaction is also possible with deactivating substituents on the aromatic group.
|
|
The first radical 1,2-rearrangement reported by Heinrich Otto Wieland in 1911 Über Triphenylmethyl-peroxyd. Ein Beitrag zur Chemie der freien Radikale Wieland, H. Chem. Ber. 1911, 44, 2550–2556. was the conversion of bis(triphenylmethyl)peroxide 1 to the tetraphenylethane 2.
|
|
Diazo compounds are used as precursors to carbenes, which are generated by thermolysis or photolysis, for example in the Wolff rearrangement. As such they are used in cyclopropanation for example in the reaction of ethyl diazoacetate with styrene.Organic Syntheses, Coll. Vol. 6, p.
|
|
In addition to that, Fritsch–Buttenberg–Wiechell rearrangement was used as crucial step during the synthesis of the longest known polyyne (C44). An elimination of chlorovinylsilanes was used as a final step in the synthesis of the longest known phenyl end-capped polyynes.
|
|
This process is more generally known as a vinylcyclopropane rearrangement. Skattebøl rearrangementThe reaction is closely related to the earlier Doering- LaFlamme procedure (Doering-LaFlamme allene synthesis), in which a gem- dibromocyclopropane is treated with an alkali metal to form the same cyclopropylidene intermediate.
|
|
Thermal bicyclo[6.1.0]nonatrienyl chloride-dihydroindenyl chloride rearrangement Paul v. R. Schleyer, James C. Barborak, Tah Mun Su, Gernot Boche, and G. Schneider J. Am. Chem. Soc.; 1971; 93(1) pp 279 - 281; Topology in Chemistry: Designing Möbius Molecules Herges, R. Chem. Rev.
|
|
Immunol Res 32:153-8, 2005. full text TCR rearrangement occurs in two steps. First the TCRβ chain is rearranged at the DN3 stage of T cell development. The TCRβ chain is paired with the pre-Tα to generate the pre-TCR.
|
|
After a sequence of cleavage and rearrangement, an organic ozonide is formed. With reductive workup (e.g. zinc in acetic acid or dimethyl sulfide), ketones and aldehydes will be formed, with oxidative workup (e.g. aqueous or alcoholic hydrogen peroxide), carboxylic acids will be formed.
|
|
This problem was particularly severe in Galveston, leading to its premature decommissioning in 1970. and had to have a large amount of ballast and internal rearrangement to allow continued service into the 1970s.Those Cleveland Class Cruisers. An exercise in expediency in N.Wilder Post.
|
|
The α-ketol rearrangement is the acid-, base-, or heat-induced 1,2-migration of an alkyl or aryl group in an α-hydroxy ketone or aldehyde to give an isomeric product.Paquette, L. A.; Hofferberth, J. E. Org. React. 2003, 62, 477–567.
|
|
At the recording session, the group was presented with a rearrangement of "Heart and Soul" that was more formal than they had practiced. The group added unexpected rhythms to give the song a syncopated feel. "Heart and Soul" sat undistributed until 1961.
|
|
Rearrangement of dimers (e.g., Mad:Max, Max:Myc) provides a system of transcriptional regulation with greater diversity of gene targets. Max must dimerise in order to be biologically active. Transcriptionally active hetero- and homodimers involving Max can promote cell proliferation as well as apoptosis.
|
|
A rearrangement of occupation duties saw V Corps take over the Styria zone from Soviet forces, and a line section was despatched to establish communications with 46th Division at Graz.Jackson, Vol VI, Pt III, pp. 340, 347–8.Roberts, pp. 25–6.
|
|
A route analogous to the cumene process begins with cyclohexylbenzene. It is oxidized to a hydroperoxide, akin to the production of cumene hydroperoxide. Via the Hock rearrangement, cyclohexylbenzene hydroperoxide cleaves to give phenol and cyclohexanone. Cyclohexanone is an important precursor to some nylons.
|
|
As a vicinal- diol, it can rearrange to pinacolone by the pinacol rearrangement, e.g. by heating with sulfuric acid: 550px Pinacol can be used with borane and boron trichloride to produce useful synthetic intermediates such as pinacolborane, bis(pinacolato)diboron, and pinacolchloroborane.
|
|
Rearrangement to tricyclic isomer 7 occurred, and further warming to room temperature yielded perfluorotropilidene (8). The parent quadricyclane (9) rearranges instead to norbornadiene (10), under far more vigorous conditions. unique chemistry of perfluoroquadricyclane Keto-enol equilibria are affected dramatically by fluorine substitution.
|
|
TCAG also hosts and curates websites and databases developed from supported projects, namely The Chromosome 7 Database, The Database of Genomic Variants,Database of Genomic Variants the Segmental Duplication Database, the Autism Chromosome Rearrangement Database, and others. These databases contain publicly available information.
|
|
Rigidity was particularly explored in Lewin's views regarding the degree of differentiation among children. He posited that a mentally retarded child can be distinguished from the normal child due to the smaller capacity for dynamic rearrangement in terms of his psychical systems.
|
|
The mechanism requires zinc and acetic acid as catalysts. It will proceed at room temperature. Because α-amino-ketones self-condense very easily, they must be prepared in situ. The usual way of doing this is from the relevant oxime, via the Neber rearrangement.
|
|
A molecular phylogenetic study published in 2013 found that Myrmeciza, as then defined, was polyphyletic. In the resulting rearrangement to create monophyletic genera this species was moved to the resurrected genus Akletos which had been introduced by the Polish ornithologist Andrzej Dunajewski in 1948.
|
|
The reaction is irreversible because the resulting by-products, carbonyl sulfide and methanethiol, are very stable. frameless The Chugaev elimination is very similar to the ester pyrolysis, but requires significantly lower temperatures to achieve the elimination, thus making it valuable for rearrangement-prone substrates.
|
|
3,3'-Dichlorobenzidine is prepared in two steps from 2-nitrochlorobenzene. The first step involves reduction with zinc in base to afford 3,3'-dichlorodiphenylhydrazine. This intermediate undergoes the benzidine rearrangement to afford 3,3'-dichlorobenzidine. Aqueous solutions of 3,3'-dichlorobenzidine degrade in light to monochloro derivative.
|
|
This leads to a transesterification of the sulfate group onto the aldehyde hydrate. Simultaneously the substrate alcohol is released. In the second step, sulfate is eliminated from the enzyme-sulfate intermediate by an intramolecular rearrangement. The “intramolecular hydrolysis” allows the aldehyde group to be regenerated.
|
|
Intracellular signals consist of a cell signaling itself (autocrine signaling), also play a role in organ formation. These signaling pathways allows for cell rearrangement and ensures that organs form at specific sites within the organism. The organogenesis process can be studied using embryos and organoids.
|
|
The first step is to form tricycle 118 in 16 steps. After another 6 steps, this compound is converted to enone 120. Subsequently, this allene is added to produce photoadduct 121. This adduct group is cleaved and rearrangement gives rise to the compound 122.
|
|
The Willgerodt rearrangement or Willgerodt reaction is an organic reaction converting an aryl alkyl ketone to the corresponding amide by reaction with ammonium polysulfide, named after Conrad Willgerodt.Willgerodt, Ber., 20, 2467 (1887) ; 21, 534 (1888) Carmack, M.; Spielman, M. A. Org. React. 1946, 3.
|
|
The nitration of the 2 position involves the loss of CO2 as the leaving group. Desulfonation in which a sulfonyl group is substituted by a proton is a common example. See also Hayashi rearrangement. In aromatics substituted by silicon, the silicon reacts by ipso substitution.
|
|
Susy Fuentes-Bazan, Pertti Uotila, Thomas Borsch: A novel phylogeny-based generic classification for Chenopodium sensu lato, and a tribal rearrangement of Chenopodioideae (Chenopodiaceae). In: Willdenowia. Vol. 42, No. 1, 2012, p. 16. Spinacia, Germplasm Resources Information Network - (GRIN) [Online Database], accessed 2013-07-10. .
|
|
Elastic deformation stretches the bonds between atoms away from their equilibrium radius of separation, without applying enough energy to break the inter-atomic bonds. Plastic deformation, on the other hand, breaks inter-atomic bonds, and therefore involves the rearrangement of atoms in a solid material.
|
|
26, pp. 557–563 (10)File:IntraCPScope5.png Pyrroles react with vinyl diazoacetates to form nitrogen-bridged cycloheptadienes. The use of methyl lactate as a chiral auxiliary on the vinyl diazoacetate led to moderate diastereoselectivity in the tandem cyclopropanation/Cope rearrangement of Boc-protected pyrrole.
|
|
Nitrenium ions are also intermediates in organic reactions; for instance, the Bamberger rearrangement. They can also act as electrophiles in electrophilic aromatic substitution. Phenylnitrenium ion reaction with guanine, DFT energies for 22 isomeric adducts. The term imidonium ion with the same meaning, is now obsolete.
|
|
The Skattebøl rearrangement is an organic reaction for converting a geminal dihalo cyclopropane to an allene using an organolithium base.The Formation of Allenes from gem-Dihalocyclopropanes by Reaction with Alkyllithium Reagents. William R. Moore, Harold R. Ward J. Org. Chem.; 1962; 27(12); 4179-4181 .
|
|
Several reagents can be substituted for bromine. Sodium hypochlorite, lead tetraacetate, N-bromosuccinimide, (bis(trifluoroacetoxy)iodo)benzene, and 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) can effect a Hofmann rearrangement. In the following example, the intermediate isocyanate is trapped by methanol, forming a carbamate. NBS.
|
|
Treatment with peracetic acid gives 3,4-caranediol. Pyrolysis over ferric oxide induces rearrangement, giving p-cymene. Carene is used in the perfume industry and as a chemical intermediate. Because carene can be found in cannabis naturally, it can also be found in cannabis distillates.
|
|
Cuneane (C8H8, pentacyclo[3.3.0.02,4.03,7.06,8]octane) is a saturated hydrocarbon.with 3D-structure (however molecular graph of cuneane is a planar graph) Its name is derived from the Latin cuneus, meaning a wedge. Cuneane may be produced from cubane by metal-ion-catalyzed σ-bond rearrangement.
|
|
A route to phenol analogous to the cumene process begins with cyclohexylbenzene, which is oxidized to a hydroperoxide, akin to the production of cumene hydroperoxide. Via the Hock rearrangement, cyclohexylbenzene hydroperoxide cleaves to give phenol and cyclohexanone. Cyclohexanone is an important precursor to some nylons.
|
|
The Nametkin rearrangement is the shift of a methyl group in this scheme and called the 'Nametkin' step. The shift of the ring bond is actually a standard Wagner-Meerwein shift. The reaction can in fact be used to make the terpene, using chlorocamphene.
|
|
It is a popular tridentate ligand in coordination chemistry. It is prepared from the triscarbamate of cyclohexane. The latter is generated via the Curtius rearrangement starting from cyclohexanetricarboxylic acid. Structure of [Ni(TACH)(H2O)3]2+ (color code: blue = nitrogen, red = oxygen; dark blue = nickel).
|
|
Upon warming to room temperature, the base will deprotonate the sulfonium ion creating the sulfonium ylide 4, which quickly undergoes a [2,3]-sigmatropic rearrangement to give the ketone 5. The ketone 5 will undergo a facile condensation to give the desired 3-thiomethylindole 6.
|
|
More recently, another graphical procedure has been developed in order to evaluate K and ε independently of each other. This approach relies on a more complex mathematical rearrangement of the Benesi–Hildebrand method but has proven to be quite accurate when compared to standard values.
|
|
Taxodone was first isolated in 1968 from the seeds of Taxodium distichum (Bald Cypress) by S. Morris Kupchan and coworkers. They reported the structure determination and basic chemistry of taxodone and its oxidized rearrangement product, taxodione. Taxodone occurs naturally in the form of (+)-taxodone.
|
|
4,4’-Dinitro-3,3’-diazenofuroxan (DDF) is a powerful experimental high explosive with performance comparable to that of other high-density high- explosives such as octanitrocubane. It is synthesised by oxidative coupling of 4-amino-3-(azidocarbonyl)furoxan followed by Curtius rearrangement and further oxidation.
|
|
The homoaromatic 1-hydroxyhomotropylium cation. Journal of the American Chemical Society (1967), 89(8), 1965-6.Brookhart, Maurice; Lustgarten, Ronald K.; Winstein, Saul. Bridge flipping and rearrangement of norbornadienyl and 7-methylnorbornadienyl cations. Journal of the American Chemical Society (1967), 89(24), 6352-4.
|
|
Cyclohexylbenzene can replace isopropylbenzene. Via the Hock rearrangement, cyclohexylbenzene hydroperoxide cleaves to give phenol and cyclohexanone. Cyclohexanone is an important precursor to some nylons. Starting with the alkylation of benzene with mixture of 1 and 2-butenes, the cumene process produces phenol and butanones.
|
|
1,3-Diisopropylbenzene is the aromatic hydrocarbon with the formula C6H4(CHMe2)2 (Me = CH3). It is one of three isomeric diisopropylbenzenes. This colorless liquid is prepared by thermal isomerization of 1,4-diisopropylbenzene. It is the principal industrial precursor to resorcinol via the Hock rearrangement.
|
|
On standing the anydrous acid undergoes rearrangement and disproportionation to form a mixture of isohypophosphoric acid, HPO(OH)-O-PO2(OH); pyrophosphoric acid H2P2O7 and pyrophosphorous acid. Hypophosphoric acid is unstable in hot hydrochloric acid, in 4 M HCl it hydrolyses to give H3PO3 \+ H3PO4.
|
|
Based on deuterium- labeling experiments, they concluded that alkene formation is initiated by hydride reduction of the iminium ion followed by double bond migration and nitrogen extrusion which occur in a concerted manner. Allylic diazene rearrangement as the final step in the reductive 1,3-transposition of α,β-unsaturated tosylhydrazones to the reduced alkenes can also be used to establish sp3-stereocenters from allylic diazenes containing prochiral stereocenters. The influence of the alkoxy stereocenter results in diastereoselective reduction of the α,β-unsaturated tosylhydrazone. The authors predicted that diastereoselective transfer of the diazene hydrogen to one face of the prochiral alkene could be enforced during the suprafacial rearrangement.
|
|
The original 1951 publication concerned the conversion of potassium t-butyl peroxide and 1-phenylethyl bromide to ultimately acetophenone and t-butanol with piperidine as the base: Kornblum-DeLaMare rearrangement original reaction The Kornblum–DeLaMare rearrangement can be carried out as an asymmetric reaction with a suitable chiral amine such as sparteine or a cinchona alkaloid:Enantioselective Synthesis of -Hydroxyenones by Chiral Base-Catalyzed Kornblum DeLaMare RearrangementSteven T. Staben, Xin Linghu, and F. Dean Toste J. Am. Chem. Soc.; 2006; 128(39) pp 12658 – 12659; (Communication) () :Asymmetric reaction The first step in this one-pot reaction is 1,4-dioxygenation of 1,3-cycloheptadiene with singlet oxygen and a TPP catalyst.
|
|
In type I rearrangements (Y-A-B-X conversion to X-A-B-Y) the two migrating groups are oriented trans to each other and as a result of the rearrangement they migrate to opposite sides. The first example of a dyotropic rearrangement involving a carbon-carbon bond was reported by Cyril A. Grob and Saul Winstein.Organische und biologische Chemie Mechanismus der Mutarotation von 5,6-Dibromcholestan C.A. Grob, S. Winstein Helvetica Chimica Acta Volume 35 Issue 3, Pages 782 - 802 1952 They observed the interconversion of 2 bromine atoms in a certain steroid. In a straightforward example the two bromine atoms in 3-tert-butyl-trans-1,2-dibromohexane mutarotate by heating.
|
|
The first proposed mechanism for a thermal rearrangement of an aromatic compound was for the automerization of naphthalene. It was suggested that the rearrangement of naphthalene occurred due to reversibility of the isomerization of azulene to naphthalene. This mechanism would therefore involve an azulene intermediate and is depicted below: upright=2 Subsequent work showed that the isomerization of azulene to naphthalene is not readily reversible ( the free energy of a naphthalene to azulene isomerization was too high - approximately 90 kcal/mol). A new reaction mechanism was suggested that involved a carbene intermediate and consecutive 1,2-hydrogen and 1,2-carbon shifts across the same C-C bond but in opposite directions.
|
|
Heilbronner, E.; Plattner, P. A.; Wieland, K. Rearrangement of Azulene to Naphthalene. Experientia 1947, 3, 70–71. Since then, many other isomerizations have been recorded, however the rearrangement of azulene to naphthalene has received the most attention. Likewise, since the characterization of the automerization of naphthalene by Scott in 1977, similar atom scramblings of other aromatic hydrocarbons such as pyrene,Scott, L. T.; Kirms, M. A.; Berg, A.; Hansen, P. E. Automerization of Pyrene a Test for the Mechanism of Naphthalene Automerization. Tetrahedron Letters 1982, 23 (18), 1859–1862. DOI: 10.1016/S0040-4039(00)87204-4 azulene, benz[a]anthraceneScott, L. T.; Tsang, T.-H.
|
|
Large B-cell lymphoma with IRF4 rearrangement (LBCL with IRF4 rearrangement) is a DLBCL in which tissue infiltrates containing intermediate- or large-sized neoplastic B-cells strongly express a chromosomal translocation involving the IRF4 gene on the short arm of chromosome 6. These cells form follicular, follicular and diffuse, or entirely diffuse infiltrates in Waldeyer's tonsillar ring or other regions of the head and neck. The disease, which represents ~0.05% of all DLBCL, occurs primarily in children and young adults and typically has a good prognoses. Cases with a follicular pattern of tissue infiltrates often have indolent disease and an excellent prognosis following excision and may not need chemotherapy.
|
|
The third rearrangement of crew assignment occurred when Slayton felt that See wasn't up to the physical demands of EVA on Gemini 8. He reassigned See to be the prime commander of Gemini 9 and put Scott as pilot of Gemini 8 and Charles Bassett as the pilot of Gemini 9. The fourth and final rearrangement of the Gemini crew assignment occurred after the deaths of See and Bassett when their trainer jet crashed, coincidentally into a McDonnell building which held their Gemini 9 capsule in St. Louis. The backup crew of Stafford and Cernan was then moved up to the new prime crew of Gemini 9A.
|
|
The cationic 2-aza-Cope rearrangement is characterized by its high stereospecificity, which arises from its high preference for a chair transition state. In their exploration of this rearrangement's stereospecificity, Overman and coworkers used logic similar to the classic Doering and Roth experiments, which showed that the Cope rearrangement prefers a chair conformation. By using the cationic 2-aza- Cope/Mannich reaction on pyrrolizidine precursors, they showed that pyrrolizidines with cis substituents from E-alkenes and trans substituents from Z-alkenes are heavily favored, results that are indicative of a chair transition state. If a boat transition state was operative, the opposite results would have been obtained (detailed in image below).
|
|
I. Studies in the Pregnane Series O. R. RODIG, P. BROWN, and P. ZAFFARONI J. Org. Chem. 1961, 26(7), 2431-2435\. () Westphalen–Lettré rearrangement The reaction is first-order in steroid in the presence of an excess of sulfuric acidAcid catalysed reactions of 5α-hydroxy-steroids—III : The westphalen rearrangementTetrahedron, Volume 21, Issue 6, 1965, Pages 1567-1580 J. W. Blunt, A. Fischer, M. P. Hartshorn, F. W. Jones, Kirk D. N. and S. W. Yoong () and the first reaction step in the reaction mechanism is likely the formation of a sulfate ester followed by that of a carbocation at C5 after which the actual rearrangement takes place.
|
|
2008 rearrangement, seen from Delancey Street Forsyth Street Plaza being rebuilt, 2017. It opened May 25, 2018. Forsyth Street runs from Houston Street south to Henry Street in the New York City borough of Manhattan. The street was named in 1817 for Lt. Colonel Benjamin Forsyth.
|
|
Intersystem crossing and radical recombination results in equal quantities of semibullvalenes 3 and 4. The new proton distribution with allylic, vinylic and cyclopropanyl protons determined with proton NMR confirms this model. As noted, the conversion of barrelene to semibullvalene is a di-pi-methane rearrangement. Scheme 4.
|
|
The scalloped antbird was formerly included in the genus Myrmeciza. A molecular phylogenetic study published in 2013 found that Myrmeciza, as then defined, was polyphyletic. In the resulting rearrangement to create monotypic genera four species including the scalloped antbird were moved to the resurrected genus Myrmoderus.
|
|
The reaction mechanism is that of the related Hofmann degradation. Weermann degradation 1st unsattuered At first the carbonic acid amide (1) reacts with the sodium hypochlorite. After separate water and chloride an amine with a free bond is build 2. The intermediate (3) is generated by rearrangement.
|
|
The Wallach rearrangement, also named Wallach transformation, is a name reaction in the organic chemistry. It is named after Otto Wallach, who discovered this reaction in 1880. In general it is a strong acid-promoted conversion of azoxybenzenes into hydroxyazobenzenes.Otto Wallach and E. Belli, Chem. Ber.
|
|
The Doering–LaFlamme allene synthesis entails the conversion of alkenes to allenes (a chain extension) with magnesium or sodium metal through initial reaction of the alkene with dichlorocarbene. The same sequence is incorporated in the Skattebøl rearrangement to cyclopentadienes. Closely related is the more reactive dibromocarbene CBr2.
|
|
The alternative argument is that during meiosis I, looping and homologous recombination within a sister chromatid can cause this rearrangement. A rough estimation approximates that neocentromere formation on inverted duplicated chromosomes happens every 70,000–200,000 live births. However, this statistic does not include Class II rearrangements.
|
|
The rearrangement reaction takes place by reacting the nitrosamine precursor with hydrochloric acid. The chemical yield is generally good under these conditions, but often much poorer if a different acid is used. The exact reaction mechanism is unknown but there is evidence suggesting an intramolecular reaction.
|
|
CIN often results in aneuploidy. There are three ways that aneuploidy can occur. It can occur due to loss of a whole chromosome, gain of a whole chromosome or rearrangement of partial chromosomes known as gross chromosomal rearrangements (GCR). All of these are hallmarks of some cancers.
|
|
A post office called El Jobean was established in 1924, and remained in operation until 1964. The name El Jobean is an anagram, a rearrangement of the letters of "Joel Bean", the name of the property developer who laid out the town site in the 1920s.
|
|
ANGES compares extant related genomes through ancestral reconstruction of genetic markers. BADGER uses a Bayesian approach to examining the history of gene rearrangement. Count reconstructs the evolution of the size of gene families. EREM analyses the gain and loss of genetic features encoded by binary characters.
|
|
Photo- aging is another degradation route for polycarbonates. Polycarbonate molecules (such as the aromatic ring) absorb UV radiation. This absorbed energy causes cleavage of covalent bonds which initiates the photo-aging process. The reaction can be propagated via side chain oxidation, ring oxidation or photo- Fries rearrangement.
|
|
This mixture is quantitatively dehydrogenated on a copper contact catalyst to cyclododecanone and this reacted with hydroxylamine to cyclododecanone oxime. The oxime is rearranged to laurolactam in a Beckmann rearrangement in the presence of a strong acid.Patent US8309714: Process for producing laurolactam. invent1: J. Kugimoto et al.
|
|
Carbon insertions are tremendously useful reactions which introduce an additional carbon atom into the ring. These reactions are used in the synthesis of many drugs and natural products. These can proceed through any of the mechanisms listed below. The bond migration step of the pinacol type rearrangement.
|
|
The first step is a rearrangement reaction to a cyclopentadienone intermediate 2, the second one a dimerization in a Diels- Alder reaction (3) and the third one an intramolecular [2+2]cycloaddition (4). The bursting effect is attributed to a large change in crystal volume on dimerization.
|
|
These compounds, e.g. calicheamicin, are some of the most aggressive antitumor drugs known, so much so that the ene-diyne subunit is sometimes referred to as a "warhead". Ene-diynes undergo rearrangement via the Bergman cyclization, generating highly reactive radical intermediates that attack DNA within the tumor.
|
|
At the other end of life, normal or pathological aging (neurodegenerative diseases, such as Alzheimer's disease) is also accompanied by a rearrangement of brain connections that diffusion MRI shows.Le Bihan D, Johansen-Berg H, "Diffusion MRI at 25: Exploring brain tissue structure and function", NeuroImage 2011.
|
|
Elizabeth MacGregor Hardy (born July 31, 1915 - died June 26, 2008)Ancestry.com.U.S.,Social Security Death Index, 1935-2014. Provo, UT, USA: Ancestry.com Operations Inc, 2014 was a North American chemist who discovered the Cope rearrangement while working in Arthur Cope's research group at Bryn Mawr College.
|
|
Mixing is defined as a random rearrangement of particles by means of mechanical energy, e.g. rotary devices in a fixed volume. Traces of individual components can still be located within a small quantity of the mixed material of two or more material types. Application: small-scale storage.
|
|
The Most Excellent Master Degree is considered American in origin,"Most Excellent Master Degree". Monroe Chapter No. 1, R.A.M. Accessed September 2, 2008. although it has been postulated by Denslow and Turnbull that it was merely a rearrangement of preexisting material.Denslow, Ray and Everett C. Turnbull.
|
|
In 1959, a young research chemist with Humble Oil and Refining (Esso, now Exxon) named Norman P. Neureiter was instructed to find new uses for the excess butadiene produced from one of the refinery processes. Discussions about carbene chemistry with one of the company's most respectable consultants at the time, William von Eggers Doering, then a professor at Yale, led the young Ph.D. graduate from Northwestern University to follow a recent procedure combining both, carbenes and butadiene. In particular the procedure described the reaction of 1,3-butadiene with carbenes generated from the action of base on chloroform or bromoform, which had been studied previously by Doering. Neureiter then took the resulting 1,1-dichloro-2,2-dimethylcyclopropane and under pyrolysis conditions (above 400 °C) discovered a rearrangement to 4,4-dichlorocyclopentene which today is considered to be the first thermal vinylcyclopropane-cyclopentene rearrangement in history. Vinylcyclopropane Rearrangement of 1,1-dichloro-2,2-dimethylcyclopropane to 4,4-dichlorocyclopentene The corresponding all-carbon version of the reaction was independently reported by Emanuel Vogel and Overberger & Borchert just one year after the Neureiter publication appeared.
|
|
It was subsequently moved to the genus Myrmeciza. A molecular phylogenetic study published in 2013 found that Myrmeciza was polyphyletic. In the resulting rearrangement to create monophyletic genera this species was moved to the resurrected genus Akletos which had been introduced by the Polish ornithologist Andrzej Dunajewski in 1948.
|
|
This rearrangement also leads to a substituted, but not expanded, byproduct. Thus it can be difficult to isolate the two products and acquire the desired yield. Also, stereoisomers are produced depending on the direction of addition of the water molecule and other molecules may be produced depending on rearrangements.
|
|
This gene is located in the chromosome 10q25-26 region, which is frequently deleted in gliomas and tumors of other tissues, and is disrupted by the t(10;19) translocation rearrangement in glioblastoma cells. The gene location suggests that it is a candidate gene for the tumor suppressor locus.
|
|
Despite many efforts, a definitive reaction mechanism for the Fries rearrangement has not been determined. Evidence for inter- and intramolecular mechanisms have been obtained by crossover experiments with mixed reactants. The Reaction progress is not dependent on solvent or substrate. A widely accepted mechanism involves a carbocation intermediate.
|
|
1,2-hydride shift in vinyl cation. Adapted from Orbital interactions in vinyl cation to allyl cation rearrangement. Adapted from Vinyl cations undergo 1,2-hydride shifts to form an allyl-stabilized cation. 1,2-hydride shifts are fairly common in alkyl cations and is fast in the NMR time scale.
|
|
Hydroformylation of DCP gives the dialdehyde called TCD dialdehyde (TCD = tricyclodecane). This dialdehyde can be oxidized to the dicarboxylic acid and to a diol. All of these derivatives have some use in polymer science. Hydrogenation of dicyclopentadiene gives the saturated derivative C10H16, which undergoes acid-catalyzed rearrangement to adamantane.
|
|
Trimethylsilyl enol ethers can be prepared from ketones in presence of a strong base and trimethylsilyl chloride or a weak base and trimethylsilyl triflate. Alternatively, enolate salts react with silyl electrophiles. A rather exotic way to generate silyl enol ethers is via the Brook rearrangement of appropriate substrates.
|
|
Benzidine is prepared in a two step process from nitrobenzene. First, the nitrobenzene is converted to 1,2-diphenylhydrazine, usually using iron powder as the reducing agent. Treatment of this hydrazine with mineral acids induces a rearrangement reaction to 4,4'-benzidine. Smaller amounts of other isomers are also formed.
|
|
Although it is a dienone and thus has the necessary structure for Dienone-Phenol Rearrangement, the methyl groups in positions 3 and 5 of the ring block the movement of the group at position 4, so even the action of trifluoroacetic acid will not cause transformation to a phenol.
|
|
Soils, particularly clays, display a significant amount of inelasticity under load. The causes of plasticity in soils can be quite complex and are strongly dependent on the microstructure, chemical composition, and water content. Plastic behavior in soils is caused primarily by the rearrangement of clusters of adjacent grains.
|
|
There are several genes involved in plant phototropism including the NPH1 and NPL1 gene. They are both involved in chloroplast rearrangement. The nph1 and npl1 double mutants were found to have reduced phototropic responses. In fact, the two genes are both redundant in determining the curvature of the stem.
|
|
2013.00277Stephens, P. J., Greenman, C. D., Fu, B., Yang, F., Bignell, G. R., Mudie, L. J., ... Campbell, P. J. (2011). Massive genomic rearrangement acquired in a single catastrophic event during cancer development. Cell, 144(1), 27–40. doi:10.1016/j.cell.2010.11.055Forment, J. V., Kaidi, A., & Jackson, S. P. (2012).
|
|
Some key steps in the preparation of the aza-Cope/Mannich reaction substrate for the Overman synthesis of strychnine The Overman synthesis, with in-depth details of the synthesis of the rearrangement substrate, as well as the final steps of the reaction, is detailed here: Overman synthesis of (−)-Strychnine.
|
|
No common breakpoints for the deletion were identified indicating that the 2q37 rearrangement is unlikely to be mediated by non-homologous recombination and low-copy repeats. In a study of 20 patients, no clear relationship was found between clinical features and the size or position of the monosomic region.
|
|
The discrepancy had resulted from an unanticipated skeletal rearrangement that had occurred in the Büchi synthesis when patchoulene was treated with peroxy acid, an operation that by accident generated the correct architecture of the natural product. Actual sequence for the synthesis of patchouli alcohol. Contains embedded [2.2.2]propellane motif.
|
|
Tree of Life: Amaryllidaceae In his 1963 monograph on Amaryllidaceae, Traub lists six species, Rhodophiala, Haylockia, Pyrolirion, Zephyranthes, Habranthus and Sprekelia. Meerow et al. (1999) provides an account (Table 1) of the subsequent rearrangement of Traub's genera, and of the modern molecular based phylogeny (see also Taxonomy of Amaryllidoideae).
|
|
In many cases, this resolution is all that is needed. After all, bilayers are very small only in one dimension. Laterally, a bilayer can extend for many micrometres or even millimeters. But certain phenomena like dynamic phase rearrangement do occur in bilayers on a lateral sub-micrometre lengthscale.
|
|
Early in 2007 Mast and Thiele initiated a rearrangement of Banksia by transferring Dryandra into it, and publishing B. subg. Spathulatae for the species having spoon- shaped cotyledons. All members of subseries Banksia fall within Mast and Thiele's B. subg. Banksia, but no further details have been published.
|
|
However, Guaram was not crowned as king, but recognized as a presiding prince and bestowed with the Eastern Roman title of curopalates. The Byzantine-Sassanid treaty of 591 confirmed this new rearrangement, but left Iberia divided into Roman- and Sassanid-dominated parts at the town of Tbilisi.Suny, p. 25.
|
|
The Hungarian composer Franz Liszt, who was fascinated by the Wanderer Fantasy, transcribed it for piano and orchestra (S.366) and two pianos (S.653). He additionally edited the original score and added some various interpretations in ossia, and made a complete rearrangement of the final movement (S.565a).
|
|
In multilinear algebra, a reshaping of tensors is any bijection between the set of indices of an order-d tensor and the set of indices of an order-\ell tensor, where \ell < d . The use of indices presupposes tensors in coordinate representation with respect to a basis. The coordinate representation of a tensor can be regarded as a multi-dimensional array, and a bijection from one set of indices to another therefore amounts to a rearrangement of the array elements into an array of a different shape. Such a rearrangement constitutes a particular kind of linear map between the vector space of order-d tensors and the vector space of order-\ell tensors.
|
|
TCRs have two parts, usually an alpha and a beta chain. (Some TCRs have a gamma and a delta chain.) Hematopoietic stem cells in the bone marrow migrate into the thymus, where they undergo V(D)J recombination of their beta-chain TCR DNA to form a developmental form of the TCR protein, known as pre-TCR. If that rearrangement is successful, the cells then rearrange their alpha-chain TCR DNA to create a functional alpha-beta TCR complex. This highly-variable genetic rearrangement product in the TCR genes helps create millions of different T cells with different TCRs, helping the body's immune system respond to virtually any protein of an invader.
|
|
Arguably the biggest drawback of the vinylcyclopropane rearrangement as a synthetic method is its intrinsically high activation barrier resulting in very high reaction temperatures (500-600 °C). Not only do these high temperatures allow side reactions with similar activation energies, such as homodienyl-1,5]-hydrogen shifts, to occur but also do they significantly limit the functional groups tolerated in the substrates. It was well recognized by the chemical community that in order for this reaction to become a useful synthetic method, hopefully applicable in complex natural product settings at some point, some reaction development had to be done. Some of the earliest attempts to improve the vinylcyclopropane rearrangement as a synthetic method came from the Corey group in 1972.
|
|
For molecules in dynamic equilibrium such as the 2-norbornyl cation, nuclei within each set can also be transformed to one another through rearrangements with fast reaction rates. Since the proposed dynamic equilibrium of the classical ion proponents had very fast rates of rearrangement, the first NMR studies did not favor nor invalidate any of the three proposed structures. But by using solid-state NMR analysis, one can lower the temperature of the NMR experiment to and thus significantly slow down any rearrangement phenomena. Solid-state C NMR spectra of the 2-norbornyl cation shows that carbons 1 and 2 are in identical chemical environments, which is consistent only with the non-classical picture of the 2-norbornyl cation.
|
|
Homologation reactions like the Kowalski ester homologation provide simple examples of insertion process in organic synthesis. In the Arndt-Eistert reaction, a methylene unit is inserted into the carboxyl-carbon bond of carboxylic acid to form the next acid in the homologous series. Organic Syntheses provides the example of t-BOC protected (S)-phenylalanine (2-amino-3-phenylpropanoic acid) being reacted sequentially with triethylamine, ethyl chloroformate, and diazomethane to produce the α-diazoketone, which is then reacted with silver trifluoroacetate / triethylamine in aqueous solution to generate the t-BOC protected form of (S)-3-amino-4-phenylbutanoic acid. :Homologation of N-boc-phenylalanine Mechanistically, the α-diazoketone undergoes a Wolff rearrangement to form a ketene in a 1,2-rearrangement.
|
|
A generalization of this problem applicable to ancestral reconstruction is the "multiple genome rearrangement problem": given a set of genomes and a set of allowable operations, find (i) a binary tree with the given genomes as its leaves, and (ii) an assignment of genomes to the internal nodes of the tree, such that the total number of operations across the whole tree is minimized. This approach is similar to parsimony, except that the tree is inferred along with the ancestral sequences. Unfortunately, even the single genome rearrangement problem is NP-hard, although it has received much attention in mathematics and computer science (for a review, see Fertin and colleagues). The reconstruction of ancestral genomes is also called karyotype reconstruction.
|
|
Under this act, however, all objectives of a true national park were not attained and for this reason over the next two decades, new proposals for the extension and rearrangement of the protection were put forward. Finally, in 1981, a rearrangement was achieved and the park was given a new concept and enlarged to 838 km² – the area it continues to cover to this day. The Karawank mountain range and the Kamnik Alps are also important tourist destinations, as are the Pohorje mountains. Unlike the Julian Alps, however, these areas seem to attract mostly Slovene visitors and visitor from the neighboring regions of Austria, and remain largely unknown to tourists from other countries.
|
|
The Kröhnke pyridine synthesis provides a fairly general method for generating substituted pyridines using pyridine itself as a reagent which does not become incorporated into the final product. The reaction of pyridine with α-bromoesters give the related pyridinium salt, wherein the methylene group is highly acidic. This species undergoes a Michael-like addition to α,β-unsaturated carbonyls in the presence of ammonium acetate to undergo ring closure and formation of the targeted substituted pyridine as well as pyridinium bromide.. center The Ciamician–Dennstedt rearrangement entails the ring-expansion of pyrrole with dichlorocarbene to 3-chloropyridine. Ciamician–Dennstedt Rearrangement In the Gattermann–Skita synthesis, a malonate ester salt reacts with dichloromethylamine.
|
|
In addition to his own bench research and scholarly and editorial work, Kolbe oversaw student research at Leipzig and especially at Marburg; students spending time under his tutelage included Peter Griess, Aleksandr Mikhailovich Zaitsev (known for Zaitsev's rule predicting the product composition of elimination reactions), Theodor Curtius (discoverer of diazo compounds, hydrazines, and the Curtius rearrangement), Ernst Otto Beckmann (discoverer of the Beckmann rearrangement), Carl Graebe (discoverer of alizarin), Oscar Loew, Constantin Fahlberg, Nikolai Menshutkin, Vladimir Markovnikov (first to describe carbocycles smaller and larger than cyclohexane, and known for Markovnikov's rule describing addition reactions to alkenes), Jacob Volhard, Ludwig Mond, Alexander Crum Brown (first to describe the double bond of ethylene), Maxwell Simpson, and Frederick Guthrie.
|
|
Tpr-Met was generated following a chromosomal rearrangement induced by the treatment of a human osteogenic sarcoma cell line with the carcinogen N-methyl-N'-nitronitrosoguanidine. The genomic rearrangement fuses two genetic loci,translocated promoter region, from chromosome 1q25 which encodes a dimerization leucine zipper motif, and MET, from chromosome 7q31 which contributes the kinase domain and carboxy-terminus of the Met RTK. The resulting 65 kDa cytoplasmic Tpr-Met oncoprotein forms a dimer mediated through the Tpr leucine zipper. The Tpr-Met fusion protein lacks the extracellular, transmembrane and juxtamembrane domains of c-Met receptor, and has gained the Tpr dimerization motif, which allows constitutive and ligand-independent activation of the kinase.
|
|
Lastly, spatial biases of the location at which copy number variations are most densely distributed does not seem to occur in the genome. Although it was originally detected by fluorescent in situ hybridization and microsatellite analysis that copy number repeats are localized to regions that are highly repetitive such as telomeres, centromeres, and heterochromatin, recent genome- wide studies have concluded otherwise. Namely, the subtelomeric regions and pericentromeric regions are where most chromosomal rearrangement hotspots are found, and there is no considerable increase in copy number variations in that region. Furthermore, these regions of chromosomal rearrangement hotspots do not have decreased gene numbers, again, implying that there is minimal spatial bias of the genomic location of copy number variations.
|
|
Camphorsulfonic acid, sometimes abbreviated CSA or 10-CSA is an organosulfur compound. Like typical sulfonic acids, it is a relatively strong acid that is a colorless solid at room temperature and is soluble in water and a wide variety of organic substances. This compound is commercially available. It can be prepared by sulfonation of camphor with sulfuric acid and acetic anhydride: :400x400px Although this reaction appears to be a sulfonation of an unactivated methyl group, the actual mechanism is believed to involve a retro- semipinacol rearrangement, elimination of a proton from the tertiary carbocation to form an alkene, sulfonation of the alkene intermediate, and finally, semipinacol rearrangement to re-establish the ketone function.
|
|
The light chain gene has three gene segments. These include: the light chain variable region (V), joining region (J), and constant region (C) gene segments. The variable region of light is therefore encoded by the rearrangement of VJ segments. The light chain can be either kappa,κ or lambda,λ.
|
|
In 1902, Wolff discovered that treating diazoacetophenone with silver (I) oxide and water resulted in formation of phenylacetic acid. Similarly, treatment with silver (I) oxide and ammonia formed phenylacetamide. A few years later, in an independent study, Schröter observed similar results. The reaction is occasionally called the Wolff-Schröter rearrangement.
|
|
Glycoside hydrolase family 108 CAZY GH_108 includes enzymes with lysozyme (N-acetylmuramidase) activity. A glutamic acid residue within a conserved Glu-Gly-Gly-Tyr motif is essential for catalytic activity. In bacteria, it may activate the secretion of large proteins via the breaking and rearrangement of the peptidoglycan layer during secretion.
|
|
An Investigation of Special Cases E. C. Horning, V. L. Stromberg, H. A. Lloyd J. Am. Chem. Soc., 1952, 74 (20), pp 5153–5155 :Semmler–Wolff reaction The mechanism can be shown as below: :700px The reaction is intrinsically a special case of Beckmann rearrangement combined with neighbouring group participation.
|
|
The division was merged with the Basij of Kerman Province to form the Sarallah Corps of Kerman Province during the rearrangement of the IRGC units in 2008. In 2009, Brig. Gen. Mohammad Hejazi was commander who oversaw the suppression of the civil unrest in the 2009 Iranian presidential election protests.Yaghoub Fazeli.
|
|
This is the band first release under music label Ariola Japan. The album consists of two previously released single, Celebrate and Negai. Both of those singles has received special album rearrangement under album Album version. This album was released in two formats: regular CD edition and limited CD+DVD edition.
|
|
Functional null mutations in this gene cause Carney complex (CNC), an autosomal dominant multiple neoplasia syndrome. This gene can fuse to the RET protooncogene by gene rearrangement and form the thyroid tumor- specific chimeric oncogene known as PTC2. Mutation of PRKAR1A leads to the Carney complex, associating multiple endocrine tumors.
|
|
The reaction mechanism is that of the related Hofmann degradation. Weermann degradation mechanism of Hydroxy- Carbonsäureamide At first the carbonic acid amide (1) reacts with the sodium hypochlorite. After the separation of water and chloride an amine with a free bond is built 2. The intermediate (3) is generated by rearrangement.
|
|
On 13 February 2016, it was announced that Hendy would be appointed as Assistant Cabinet Secretary and Assistant Minister to the Minister for Finance following a rearrangement in the ministry. The federal election held on 2 July 2016 saw Hendy lose the seat, with Eden-Monaro returning to Labor's Mike Kelly.
|
|
Bernard M. E. Moret (born 1953) is a Swiss-American computer scientist, an emeritus professor of Computer Science at the École Polytechnique Fédérale de Lausanne in Switzerland. He is known for his work in computational phylogenetics, and in particular for mathematics and methods for computing phylogenetic trees using genome rearrangement events.
|
|
Trimethylsilyl cyclopentadiene is an organosilicon compound with the chemical formula C5H5Si(CH3)3. It exists as a colorless liquid. It is used in the synthesis of some metal cyclopentadienyl complexes and has attracted interest for its fluxional structure. Trimethylsilyl cyclopentadiene is an example of a molecule that undergoes rapid sigmatropic rearrangement.
|
|
In addition to Leighton's novel methods for synthesizing natural products, including: CP-263,114,An Approach to the Synthesis of CP-263,114: A Remarkably Facile Silyloxy-Cope Rearrangement. J. Am. Chem. Soc. 1999, 121, 890-891. Leucascandrolide A,Total Synthesis of Leucascandrolide A. J. Am. Chem. Soc. 2000, 122, 12894-12895.
|
|
Acyl halides and anhydrides of carboxylic acids are also commonly used acylating agents. In some cases, active esters exhibit comparable reactivity. All react with amines to form amides and alcohols to form esters by nucleophilic acyl substitution. Acylation can be used to prevent rearrangement reactions that would normally occur in alkylation.
|
|
Halonium ylides can be prepared from allyl halides and metal carbenoids. After a [2,3]-rearrangement a homoallylhalide is obtained. The active form of Tebbe's reagent is often considered a titanium ylide. Like the Wittig reagent, it is able to replace the oxygen atom on carbonyl groups with a methylene group.
|
|
Camphorsultam also acts as a chiral auxiliary in Michael addition. Lithium base promoted stereoselective Michael addition of thiols to N-mcthacryloylcamphorsultam produced the corresponding addition products in high diastereoselectivity. Camphorsultam was used as a chiral auxiliary in Michael addition. Camphorsultam was used as a chiral auxiliary for the asymmetric Claisen rearrangement.
|
|
Hansjörg Grützmacher, Christina M. Marchand (1997), "Heteroatom stabilized carbenium ions", Coord. Chem. Rev., 163, 287–344. Carbenium ions may undergo rearrangement reactions from less stable structures to equally stable or more stable ones with rate constants in excess of 109 s−1. This fact complicates synthetic pathways to many compounds.
|
|
Type I dyotropic rearrangements also occur around carbon-oxygen bonds, such as the thermal equilibration of RRSi1R3C-O-Si2R3 to RRSi2R3C-O-Si1R3. The 1,2-Wittig rearrangement can also be considered an example of this reaction type. More dyotropic reactions are found involving N-O bonds and N-N bonds.
|
|
A molecular phylogenetic study published in 2010 found that the genus Grus, as then defined, was polyphyletic. In the resulting rearrangement to create monophyletic genera, the Siberian crane was moved to the resurrected genus Leucogeranus. The genus Leucogeranus had been introduced by the French biologist Charles Lucien Bonaparte in 1855.
|
|
The methoxy and hydroxyl rearrangement display clear evidence that the neighboring groups are not affected in the disproportionation reaction. The "disproportionation" reactions that Benson and Buss refer to are termed loosely as "radical disproportionation" reactions.International Union of Pure and Applied Chemistry. "disproportionation". Compendium of Chemical Terminology (Accessed December 03, 2008).
|
|
2,3-Sigmatropic rearrangements are a type of sigmatropic rearrangements and can be classified into two types. Rearrangements of allylic sulfoxides, amine oxides, selenoxides are neutral. Rearrangements of carbanions of allyl ethers are anionic. The general scheme for this kind of rearrangement is: center Atom Y may be sulfur, selenium, or nitrogen.
|
|
The process in which the two gametes from the two parents unite is called fertilization. Half of the genetic information from both parents is combined. This results in offspring that are genetically different from each other and from the parents. In short, sexual reproduction allows a continuous rearrangement of genes.
|
|
Phosphorylated ephexin1 can then activate the small GTPase, RhoA, leading to subsequent activation of its effector, Rho-kinase (ROCK), which results in the rearrangement of actin filaments. Through this mechanism, astrocytic processes are able to stabilize individual dendritic protrusions as well as their maturation into spines via ephrin/EphA signaling.
|
|
DOI: 10.1016/S0010-2180(99)00032-2 upright=2 Scott's flash vacuum pyrolysis syntheses of corannulene. Many of the polycyclic aromatic hydrocarbons known to be tumorigenic or mutagenic are found in atmospheric aerosols, which is connected to the thermal rearrangement of polycyclic aromatic hydrocarbons in fast soot formation during combustion.
|
|
By the 1970s, the rearrangement had achieved synthetic utilityWender, P. A.; Eissenstat, M. A.; Filosa, M. P. J. Am. Chem. Soc. 1979, 101, 2196. and to this day it continues to be a useful method for the formation of seven-membered rings. Variations incorporating heteroatoms have been reported (see below).
|
|
Next, the thermal decarboxylation takes place through the acid chloride (with thionyl chloride) and the tert-butyl perester 6 (with tert- butyl hydroperoxide and pyridine) to 7; afterward, the acetal is once more removed in 8. A second Favorskii rearrangement gives 9, and finally another decarboxylation gives, via 10, cubane (11).
|
|
The levels of mRNA and protein present in the plant were dependent upon the age of the plant. This suggests that the phototropin expression levels change with the maturation of the leaves. Mature leaves contain chloroplasts that are essential in photosynthesis. Chloroplast rearrangement occurs in different light environments to maximize photosynthesis.
|
|
The rearrangement is shown, as well as the reaction's final products. E-alkenes are pictured in the top half, Z-alkenes in the bottom half. Operative chair transition states are detailed first, boat transition states second. Major products are labeled, and unobserved minor products of boat transition states are depicted.
|
|
2,5-Dihydrofuran is an organic compound classified as a monounsaturated derivative of furan. It is a colorless, volatile liquid. It can be produced by the rearrangement of the epoxide of butadiene.G. Wytze Meindersma, Matthias Maase and André B. Haan "Ionic Liquids" in Ullmann's Encyclopedia Of Industrial Chemistry 2007, Wiley-VCH, Weinheim.
|
|
The group followed that song with "For Sentimental Reasons" (1962), a rearrangement of a 1936 song of the same name. However, the British Invasion of the mid-1960s took the audiences of The Cleftones and other doo-wop groups. Gene Pearson left to sing with The Drifters from 1962 to 1966.
|
|
During the compaction process, if the loading pressure is increasing straightly, the powder assembly will experience three stages. First of all, particles are filling the voids and set up contacts with the adjacent particles. This stage is termed rearrangement stage. After most contacts are set up, the initial compaction started.
|
|
Benzil is a standard building block in organic synthesis. It condenses with amines to give diketimine ligands. A classic organic reaction of benzil is the benzilic acid rearrangement, in which base catalyses the conversion of benzil to benzilic acid. This reactivity is exploited in the preparation of the drug phenytoin.
|
|
A molecular phylogenetic study published in 2010 found that the genus Grus was polyphyletic. In the subsequent rearrangement, four species were placed in the resurrected genus Antigone. The genus had initially been erected in 1853 by the German naturalist Ludwig Reichenbach. The type species is the sarus crane (Antigone antigone).
|
|
Wolastoqiyik Lintuwakonawa is the debut album by Canadian composer and tenor Jeremy Dutcher, released in 2018."Jeremy Dutcher's Innovative 'Wolastoqiyik Lintuwakonawa' Is Really About the Future". Exclaim!, April 16, 2018. The album, featuring post-classical rearrangement of traditional First Nations music, was the winner of the 2018 Polaris Music Prize.
|
|
Otto Dimroth (28 March 1872 – 16 May 1940) was a German chemist. He is known for the Dimroth rearrangement, as well as a type of condenser with an internal double spiral, the Dimroth condenser. His son Karl Dimroth was also a renowned chemist, who described the first synthesis of 3-benzoxepin.
|
|
These figures are subject to continual change, as more species are discovered, and as DNA studies compel rearrangement of the taxonomy of the family. The two main subfamilies are the Anophelinae and Culicinae, with their genera as shown in the subsection below.Walter Reed Biosystematics Unit. Wrbu.si.edu. Retrieved on 2013-04-01.
|
|
Carbon monoxide is found to react with trialkylboranes. What follows is a 1,2-rearrangement whereby an alkyl substituent migrates from boron to the carbon of the carbonyl group. Homologated primary alcohols result from the treatment of organoboranes with carbon monoxide and a hydride.Rathke, M. W.; Brown, H. C. J. Am. Chem. Soc.
|
|
J. C. Nicholson (Australia) proposes a hydrogen transfer reaction that will come to be known as the McLafferty rearrangement. :1959 ::Researchers at Dow Chemical interface a gas chromatograph to a mass spectrometer. :1964 ::British Mass Spectrometry Society established as first dedicated mass spectrometry society. It holds its first meeting in 1965 in London.
|
|
While known since 1902, the Wolff rearrangement did not become synthetically useful until the early 1930s, when efficient methods became available to synthesize α-diazocarbonyl compounds. The primary ways to prepare these substrates today are via the Arndt-Eistert procedure, the Franzen modification to the Dakin-West reaction, and diazo-transfer methods.
|
|
This π-complex is not found in the H3O+(H2O)6. beckmann rearrangement mechanism acetophenone oxime With the cyclohexanone-oxime, the relief of ring strain results in a third reaction mechanism, leading directly to the protonated caprolactam in a single concerted step without the intermediate formation of a π-complex or σ-complex.
|
|
Nikolay Yakovlevich Demyanov (; , Tver – March 19, 1938, Moscow), also known as Demjanov and Demjanow, was a Russian organic chemist and a member of the USSR Academy of Sciences (1929). He is internationally known for the Demjanov rearrangement organic reaction and other discoveries. He was a recipient of the Lenin Prize in 1930.
|
|
Disilenes are generally synthesized by reduction of 1,2-dihalodisilane, by retro-Diels–Alder fragmentation, by dimerization of silylenes, by photofragmentation of cyclopolysilanes, or by rearrangement of silylsilylenes. A series of 1,1,1,4,4,4-hexaalkyl-2,3-bis(trialkylsilyl)tetrasil-2-enes structural analogues are typically synthesised using reductive coupling of the corresponding 1,1,1,3,3,3-hexaalkyl-2,3-tribromotrisilanes.
|
|
In acyloxy groups the acyl group is bonded to oxygen: R−C(=O)−O−R′ where R−C(=O) is the acyl group. Acylium ions are cations of the type R−C+=O ↔ R−C≡O+ and play an important role as intermediates in organic reactions for example the Hayashi rearrangement.
|
|
Mixed Up: I've Remix Style is a remix album by Japanese music production unit I've Sound. It was released on December 29, 2004 at the 2004 winter Comic Market event. Each of the I've Sound composers contribute to the rearrangement of one or more of the ten tracks performed by ten different singers.
|
|
Longistyles apparently is not, as its members fall into three widely separated clades. Early in 2007 Mast and Thiele initiated a rearrangement of Banksia by transferring Dryandra into it, and publishing B. subg. Spathulatae for the species having spoon-shaped cotyledons. All members of subseries Longistyles with within Mast and Thiele's B. subg.
|
|
Medical Terminology for Health Professions. Independence, Kentucky: Cengage Learning. Lutzner cells develop because of clonal gene rearrangements in the T-cell receptor or antibody. This rearrangement occurs early in the differentiation process and creates novel T-cell receptors that mimic the structure of normal antibodies but are not able to function properly.
|
|
The rearrangement of the Moscow District of the VVS and PVO into the Special Purpose Command is apparently connected with plans in the long term for the military-space defense of the central industrial region. The initial commanding officer of the KSpN was General Lieutenant Yuri Solovyov, later promoted to Colonel-General.
|
|
At this time, no studies demonstrate genome-wide rearrangement events directly giving rise to pathogenic behavior in a microbe. This does not mean it is not possible. Genome-wide rearrangements do, however, contribute to the plasticity of bacterial genome, which may prime the conditions for other factors to introduce, or lose, virulence factors.
|
|
Chromosomal reciprocal translocation of the 4th and 20th chromosome. In genetics, chromosome translocation is a phenomenon that results in unusual rearrangement of chromosomes. This includes balanced and unbalanced translocation, with two main types: reciprocal-, and Robertsonian translocation. Reciprocal translocation is a chromosome abnormality caused by exchange of parts between non-homologous chromosomes.
|
|
Chromosome analysis, also known as karyotyping refers to testing that assesses whether the expected number of chromosomes are present, whether there is any rearrangement of the chromosomes, and also whether there are any large deletions or duplications. This technology can not detect single letter changes (single nucleotide variants) or small deletions or duplications.
|
|
Zingiberene is formed in the isoprenoid pathway from farnesyl pyrophosphate (FPP). FPP undergoes a rearrangement to give nerolidyl diphosphate. After the removal of pyrophosphate, the ring closes leaving a carbocation on the tertiary carbon attached to the ring. A 1,3-hydride shift then takes place to give a more stable allylic carbocation.
|
|
The mechanism of the Boekelheide reaction begins by an acyl transfer from the trifluoroacetic anhydride to the N-oxide oxygen. The α-methyl carbon is then deprotonated by the trifluoroacetate anion. This sets the molecule up for a [3.3]-sigmatropic rearrangement which furnishes the trifluoroacetylated methylpyridine. Hydrolysis of the trifluoroacetate releases the hydroxymethylpyridine.
|
|
This appointment made her one of the 10 women appointed to Bachelet's historic half-female, half-male cabinet. On March 27, 2007 Velaso was replaced as minister by the Socialist lawyer José Antonio Viera-Gallo as part of Bachelet's rearrangement of the cabinet in the midst of fallout over the handling of Transantiago.
|
|
The taxon was created by Stephen Blair Hedges, William Edward Duellman and Matthew P. Heinicke in 2008. The taxonomy of these frogs is not yet settled, and other sources may treat the subfamily Strabomantinae as a family, Strabomantidae, with correspondingly smaller Craugastoridae. The most recent rearrangement of subfamilies and genera is from 2014.
|
|
Further, production of the required starting material is often straightforward. The modification was first proposed in 1964 by Berson and Jones, who coined the term. The driving force is the formation of a carbonyl via spontaneous keto-enol tautomerization. 526x526px Base accelerates the reaction by 1010-1017, the anionic oxy-Cope rearrangement.
|
|
A rearrangement was achieved and the park was given a new concept and expanded to 838 km². In 2010, the park expanded to include the settlement Kneške Ravne (Tolmin), according to wishes of its inhabitants, thus the new park area amounts to 880 km², which is 4% of the area of Slovenia.
|
|
In 1960, Vogel discovered that 1,2-divinylcyclopropane rearranges to cycloheptan-1,4-diene.,Vogel, E. Angew. Chem. 1960, 72, 4. After his discovery, a series of intense mechanistic investigations of the reaction followed in the 1960s, as researchers realized it bore resemblance (both structural and mechanistic) to the related rearrangement of vinylcyclopropane to cyclopentene.
|
|
Lea & Febiger, Philadelphia. Chlorinated amino acids rapidly decompose, but protein chloramines are longer-lived and retain some oxidative capacity. Thomas et al. concluded from their results that most organic chloramines decayed by internal rearrangement and that fewer available NH2 groups promoted attack on the peptide bond, resulting in cleavage of the protein.
|
|
In this case, Lewis-acidic conditions switched the sense of stereoselectivity observed for the base-catalyzed process. (3)File:Ketol stereo.png α-Hydroxy imines may also undergo rearrangement to amino ketones. Hammett analysis and a very negative entropy of activation suggest that the reaction proceeds in a single step through a concerted transition state.
|
|
Molecule "A" has been reconfigured for clarity. The rearrangement substrate proceeds by heating at 80°C in paraformaldehyde, acetonitrile, and anhydrous Na2-SO4. The paraformaldehyde adds the carbon to the nitrogen, resulting in the iminium ion, already pictured. The aza- Cope/Mannich reaction step proceeded in near quantitative yield (98%), 99% ee.
|
|
Solid acids are used in catalysis in many industrial chemical processes, from large-scale catalytic cracking in petroleum refining to the synthesis of various fine chemicals. One large scale application is alkylation, e.g., the combination of benzene and ethylene to give ethylbenzene. Another application is the rearrangement of cyclohexanone oxime to caprolactam.
|
|
Since both and are between and , they must be equal. Therefore, the terms , , ..., when reduced modulo must be distinct. To summarise: when we reduce the numbers , , ..., modulo , we obtain distinct members of the sequence , , ..., . Since there are exactly of these, the only possibility is that the former are a rearrangement of the latter.
|
|
Though spontaneous rearrangements of PGH2 are known to generate prostaglandins (PG) PGD2 and PGE2. Prof. Robert Salomon at Case Western Reserve University discovered that a novel alternative rearrangement also occurs that producing two γ-ketoaldehydes and named them levuglandins LGD2 and LGE2 as they are derivatives of levulinaldehyde with prostanoid side chains.
|
|
The trans-cis-trans isomer of the König salt (6a) can react by either sigmatropic rearrangement or nucleophilic addition of a zwitterionic intermediate to give cyclized intermediate (7). This has been suggested to be the rate-determining step.Marvell, E. N.; Caple, G.; Shahidi, I. J. Am. Chem. Soc. 1970, 92, 5641-5645.
|
|
NeuroLSD1 increases the expression of immediate early genes (IEGs) involved in cell maturation. Recurring stimuli lead to differential expression of neuroLSD1, leading to rearrangement of loci. The eraser is also thought to play a major role in the learning of many complex behaviors and is way through which genes interact with the environment.
|
|
There is a disruption of lipid metabolism. It is known that dietary rearrangement of lipid metabolism can give protection against nematode infections. Dietary poly unsaturated fatty acids (PUFA) omega-3 and omega-6 can boost up the protection. Therefore, treatment with omega-3 PUFA has been associated low egg count in the feces.
|
|
In the reaction mechanism for this organic reaction the base abstracts the acidic α-proton of the peroxide 1 to form the carbanion 4 as a reactive intermediate which rearranges to the ketone 2 with expulsion of the hydroxyl anion 3'. This intermediate gains a proton forming the alcohol 3. :Kornblum-DeLaMare rearrangement Mechanism Deprotonation and rearrangement can also be a concerted reaction without formation of 4. An alternative reaction mechanism involving direct nucleophilic displacement on the peroxide link of the amine followed by an elimination reaction is considered unlikely based on the outcome of this model reaction:The mechanism of the tertiary amine catalysed isomerisation of endoperoxides to hydroxyketones: synthesis and chemistry of the intermediate postulated in the peroxide attack mechanism David R. Kelly, Harjinder Bansal and J. J. Gwynfor Morgan Tetrahedron Letters Volume 43, Issue 51 , 16 December 2002, Pages 9331–9333 :Kornblum-DeLaMare rearrangement alternative mechanism The peroxide 1 converts to the hydroxyketone 2 by action of triethylamine but the alternative route through hydroxylamine 3 by nucleophilic displacement with Lithium diisopropylamide and the ammonium salt 4 (by methylation with methyl trifluoromethanesulfonate) fails.
|
|
The first step is likely to be a rearrangement of the reducing sugar end of the cellulose (or lactose) into a keto sugar, the second step is likely to be a reaction similar to the base catalyzed dehydration which often occurs after an aldol reaction. In this second step an alkoxide (derived from a sugar) takes the role of the hydroxide leaving group, this second step is not likely to require the lewis acidity of the calcium. The final step is a benzilic acid rearrangement from a 1,2-diketone (1,5,6-trihydroxyhexane-2,3-dione) which is formed from the carbohydrate. Under acidic conditions sugars tend to form furans such as furfural and 5-hydroxymethylfurfural by a series of dehydrations of the carbohydrate.
|
|
The aldehydes and ketones provided material for his earlier work. He observed that aldehydes and ketones may suffer reduction in neutral, alkaline, and sometimes acid solution to secondary and tertiary glycols, substances which he named pinacones; and also that certain pinacones when distilled with dilute sulfuric acid gave compounds, which he named pinacolines. The unsaturated acids also received much attention, and he discovered the internal anhydrides of oxyacids, termed lactones. He also discovered what is now known as the pinacol rearrangement, whereby 1,2-diols rearrange to aldehydes or ketones under acid catalysis. His work involved the preparation of 2,3-dimethyl-2,3-butanediol (pinacol) from acetone, followed by the rearrangement to 3,3-dimethylbutanone (pinacolone), which was then oxidised with dichromate to trimethylacetic acid.
|
|
Sam Loyd's paradoxical dissection Sam Loyd's paradoxical dissection demonstrates two rearrangements of an 8×8 square. In the "larger" rearrangement (the 5×13 rectangle in the image to the right), the gaps between the figures have a combined unit square more area than their square gaps counterparts, creating an illusion that the figures there take up more space than those in the original square figure. In the "smaller" rearrangement (the shape below the 5×13 rectangle), each quadrilateral needs to overlap the triangle by an area of half a unit for its top/bottom edge to align with a grid line, resulting overall loss in one unit square area. Mitsunobu Matsuyama's "paradox" uses four congruent quadrilaterals and a small square, which form a larger square.
|
|
Oxidation von Amiden mit N-Hydroxyphthalimid Efficient oxidation reactions of precursors of important basic chemicals are of particular technical interest. For example, ε-caprolactam can be prepared using NHPI from the so-called KA oil ("ketone- alcohol" oil, a mixture of cyclohexanol and cyclohexanone) which is obtained during the oxidation of cyclohexane. The reaction proceeds via cyclohexanol hydroperoxide which reacts with ammonia to give peroxydicyclohexylamine followed by a rearrangement in the presence of catalytic amounts of lithium chloride. Oxidation von KA-Öl zu Caprolactam The use of N-hydroxyphthalimide as a catalyst in the oxidation of KA oil avoids the formation of the undesirable by-product ammonium sulfate which is produced by the conventional ε-caprolactam synthesis (Beckmann rearrangement of cyclohexanone oxime with sulfuric acid).
|
|
Simultaneously with the shift, a pi bond forms from the oxygen to carbon, assisting in driving the migrating group off its position. The result is a ketone or aldehyde.Strategic applications of named reactions in organic synthesis: background and detailed mechanisms László Kürti, Barbara Czakó 2005 In another definition all semipinacol rearrangements "share a common reactive species in which an electrophilic carbon center, including but not limited to carbocations, is vicinal to an oxygen-containing carbon and can drive the 1,2-migration of a C–C or C–H bond to terminate the process, generating a carbonyl group ".Semipinacol Rearrangement in Natural Product Synthesis Zhen-Lei Song, Chun- An Fan, Yong-Qiang Tu Chemical Reviews The rearrangement reaction can be classified into 4 types.
|
|
When the military result was not finalized, Pelopidas was summoned to enter the protracted struggle between Alexander II and Ptolemy Aloros in Macedonia- the Theban general, however, urged rearrangement of the Thessalian League at that time. The most important parts of the rearrangement were the replacement of the tagos by an archon, and the reorganization of the Thessalian army according to the four tetrads of Aleuas. Pelopidas’ death during the battle assured continuous regional civil war. In the late summer of 358 BCE, Alexander II of Pherae's death opened a path for Philip’s diplomatic conquest of Thessaly at the request of Cineas of Larissa. The civil war in Thessaly lasted for six years until Philip’s intervention put an end to it.
|
|
3,9-Divinyl-2,4,8,10-tetraoxaspiro[5.5]undecane is without impurity a white crystalline powder. However, DVTOSU is often sold as a liquid, due to its low crystallization tendency. The highly variable data on yields and boiling points during the first fractionated distillation indicate by-products, e.g. by rearrangement of the double bonds or nucleophilic addition.
|
|
In the mid 1960s, the director created a task force to work on peptides. In this rearrangement, Ondetti came to work with Emily Sabo. During Squibb's effort to synthesis secretin, Ondetti stopped carrying a lab notebook. He considered Sabo to be such an accurate and skilled chemist, that he let her do all the experiments.
|
|
He was the first chemist to synthesize the quaternary amines. His method of converting an amide into an amine is known as the Hofmann rearrangement. While primary, secondary, and tertiary amines were stable when distilled at high temperatures under alkaline conditions, the quaternary amine was not. Heating quaternary tetraethylammonium hydroxide yielded tertiary triethylamine vapour.
|
|
Cyclopropanol is an organic compound with the chemical formula C3H6O. It contains a cyclopropyl group with a hydroxyl group attached to it. The compound is highly unstable due to the three-membered ring, and is susceptible to reactions that open the ring. It is highly prone to rearrangement, undergoing structural isomerization to form propanal.
|
|
A molecular phylogenetic study published in 2013 found that the genus Myrmeciza, as then defined, was polyphyletic. In the resulting rearrangement to create monophyletic genera the Yapacana antbird was moved to its own genus Aprositornis. The name of the genus combines the Ancient Greek words aprositos "unapproachable" or "hard to get at" and ornis "bird".
|
|
The volume is dated 1867 but the issue was published in the following year. The species was later included in the genus Myrmeciza. A molecular phylogenetic study published in 2013 found that Myrmeciza was polyphyletic. In the resulting rearrangement to create monophyletic genera the sooty antbird was moved to the newly erected genus Hafferia.
|
|
The imported data can be visualized through visualizer components and filters can be applied to the data. The filter components range from simple data rearrangement to more advanced FFT and outlier removal filters. The visualizers include a variety of plots and grids, which can be interconnected and branched out to perform complex data mining tasks.
|
|
The reaction of tertiary alcohols containing an α-acetylenic group does not produce the expected aldehydes, but rather α,β-unsaturated methyl ketones via an enyne intermediate.Rupe, H.; Kambli, E. Helv. Chim. Acta 1926, 9, 672. ()Li, J.J. In Rupe rearrangement; Name Reactions: A Collection of Detailed Reaction Mechanisms; Springer: Berlin, 2006; pp 513–514.
|
|
German Chemical Society commemorating Hans Meerwein, located at the University of Marburg Hans Meerwein (May 20, 1879 in Hamburg, Germany – October 24, 1965 in Marburg, Germany) was a German chemist. Several reactions and reagents bear his name, most notably the Meerwein–Ponndorf–Verley reduction, the Wagner–Meerwein rearrangement, the Meerwein arylation reaction, and Meerwein's salt.
|
|
Several of his twelve monographs are collaborations with Nobel Laureates J.A. Pople, H.C. Brown and G.A. Olah. In his research, Schleyer has made contributions in the area of synthesis of adamantane and other cage molecules by rearrangement mechanisms. He also discovered new types of hydrogen bonding. Schleyer also identified solvolysis mechanisms, including reactive intermediates.
|
|
Photoproducts from vinyl iodonium salt. Note: products from possible vinyl cation rearrangement not pictured here. Adapted from Recently, vinyl cation reactive intermediates have been generated in photochemical solvolysis reactions. The figure to the right depicts photochemical solvolysis of vinyl iodonium salt, through heterolytic carbon-iodine bond cleavage, to generate a vinyl carbocation and iodobenzene.
|
|
Repair work was delayed because a complete rearrangement of the yard was under consideration but as this did not proceed, tenders were called for renovations in 1974. Substantial changes were made to the structure including a new goods office, reconstruction of much of the timber platform, a new concrete platform and a new toilet.
|
|
The Ferrier carbocyclization (or Ferrier II reaction) is an organic reaction that was first reported by the carbohydrate chemist Robert J. Ferrier in 1979. It is a metal-mediated rearrangement of enol ether pyrans to cyclohexanones. Typically, this reaction is catalyzed by mercury salts, specifically mercury(II) chloride. 600px Several reviews have been published.
|
|
This is likely due to the longer aging and environmental exposure of both Jinhua and Iberian hams. The fragrant compounds consist of aldehydes, sulfur compounds such as methanethiol and dimethyl disulfide, and branched alkenes, which are derived from the breakdown and rearrangement of amino acids and fatty acids caused by auto-oxidation and fermentation.
|
|
Pigeon hole mail boxes can be mounted upon caster feet allowing for rearrangement of boxes to meet current processing demands. Cubbies are also used in American preschools and kindergartens as places to store backpacks, lunchboxes, and jackets. In large organisations the mailboy delivers mail to departmental pigeon holes from the postroom (UK) or mailroom (US).
|
|
Shchelochkov O et al., Mosaicism for r(X) and der(X)del(X)(p11.23)dup(X)(p11.21p11.22) Provides Insight into the Possible Mechanism of Rearrangement, Molecular Cytogenetics 2008, 1:16 Small supernumary rings can also form, resulting in a partial trisomy. Ring chromosomes are unstable during cell division and can form interlocking or fused rings.
|
|
However, electrophilic substitution is relatively facile at the 5-position, including nitration and halogenation. Reduction in resonance stabilization of pyrimidines may lead to addition and ring cleavage reactions rather than substitutions. One such manifestation is observed in the Dimroth rearrangement. Pyrimidine is also found in meteorites, but scientists still do not know its origin.
|
|
Susy Fuentes-Bazan, Pertti Uotila, Thomas Borsch: A novel phylogeny-based generic classification for Chenopodium sensu lato, and a tribal rearrangement of Chenopodioideae (Chenopodiaceae). In: Willdenowia. Vol. 42, No. 1, 2012, p. 5-24. Gelin Zhu, Sergei L. Mosyakin & Steven E. Clemants: Chenopodium - In: Wu Zhengyi, Peter H. Raven, Deyuan Hong (Hrsg.): Flora of China.
|
|
The Schirra and Young mission was bumped to Gemini 6 and they became the backup crew for Shepard and Stafford. Grissom and Borman then had their long-duration mission assigned to Gemini 5. The second rearrangement occurred when Shepard developed Ménière's disease, an inner ear problem. Grissom was then moved to command Gemini 3.
|
|
Brain Struct Funct. 219: 269–81. doi:10.1007/s00429-012-0498-y. . Damage to the superior parietal lobule can cause contralateral astereognosis and hemispatial neglect. It is also associated with deficits on tests involving the manipulation and rearrangement of information in working memory, but not on working memory tests requiring only rehearsal and retrieval processes.
|
|
As a pure material, bronopol has a melting point of about 130 °C. However, due to its polymorphic characteristics, bronopol undergoes a lattice rearrangement at 100 to 105 °C and this can often be wrongly interpreted as the melting point. At temperatures above 140 °C, bronopol decomposes exothermically releasing hydrogen bromide and oxides of nitrogen.
|
|
Jack Saunders joined the station and presented Radio 1 Indie Show from Mon-Thu 11pm-1am. Other changes include the shows rearrangement of Sunday evenings. Phil Taggart's chillest show moved to 7-9pm, then followed by The Rock Show with Daniel P Carter at 9-11pm. The changes took into effect in September 2018.
|
|
Ribonuclease T2 is an enzyme that in humans is encoded by the RNASET2 gene. It is a type of endoribonuclease. This ribonuclease gene is a novel member of the Rh/T2/S-glycoprotein class of extracellular ribonucleases. It is a single copy gene that maps to 6q27, a region associated with human malignancies and chromosomal rearrangement.
|
|
The country would go on to experience more than 70 flash floods between the year 2010 and 2013. In May 2011, in a cabinet rearrangement, Yaacob became Minister for Information, Communication and the Arts. He continues to serve as the Minister-in-charge of Muslim Affairs. Yaacob is on the PAP Central Executive Committee as Vice- Chairman.
|
|
For any series, we can create a new series by rearranging the order of summation. A series is unconditionally convergent if any rearrangement creates a series with the same convergence as the original series. Absolutely convergent series are unconditionally convergent. But the Riemann series theorem states that conditionally convergent series can be rearranged to create arbitrary convergence.
|
|
Four competitors from Norway who were chosen to compete boycotted the event. They objected because the hill was bigger than allowed at the time. They demanded a hill rearrangement to the K80 standard. When negotiation with the organizers failed, they left the event the middle of the trial round and under the leadership of Sigmund Ruud.
|
|
There are substantial solvent effects observed in the Claisen rearrangement, where polar solvents tend to accelerate the reaction to a greater extent. Hydrogen-bonding solvents gave the highest rate constants. For example, ethanol/water solvent mixtures give rate constants 10-fold higher than sulfolane. Trivalent organoaluminium reagents, such as trimethylaluminium, have been shown to accelerate this reaction.
|
|
It participated in various operations of the Iran–Iraq War. Its notable commander was Mehdi Bakeri After Bakeri's death in Operation Badr, Amin Shari'ati was appointed as its new commander. The division was merged with the Basij of East Azerbaijan Province to form the East Azerbaijan Ashura Provincial Corps during the rearrangement of the IRGC units in 2008.
|
|
Despite being an aggressive leukemia, the MLL1 rearranged sub-type had the lowest mutation rates reported for any cancer. Mutations in MLL1 cause Wiedemann-Steiner syndrome and Acute lymphoblastic leukemia. The leukemia cells of up to 80 percent of infants with ALL-1 have a chromosomal rearrangement that fuses the MLL1 gene to a gene on a different chromosome.
|
|
Different reaction conditions can favor the fragmentation over the rearrangement. 315x315px Quaternary carbon centers promote fragmentation by stabilizing carbocation formation through hyperconjugation. As shown in the above picture, the "stable" carbocation is formed, which then loses a hydrogen to give a site of unsaturation. Oxygen and nitrogen atoms also promote fragmentation through the formation of ketones and imines respectively.
|
|
Pyridynes were first postulated by Levine and Leake in 1955.Rearrangement in the Reaction of 3-Bromopyridine with Sodium Amide and Sodioacetophenone ROBERT LEVINE and WILLIAM W. LEAKE Science 27 May 1955: Vol. 121 no. 3152 p. 780 In 1969 Zoltewicz and Nisi trapped 3,4-pyridyne in a reaction of 3-bromopyridine with methylmercaptan and sodium amide in ammonia.
|
|
Studies on hominids have shown that, in general, males tend to have a greater increase of facial volume than of neurocranial volume, a more obliquely oriented foramen magnum, and a more pronounced rearrangement of the nuchal region.Berge C, Penin X.2004. Ontogenetic allometry, heterochrony, and interspecific differences in the skull of African apes, using tridimensional procrustes analysis.
|
|
Two-thirds of the District of Römhild went to Saxe- Meiningen. Saxe-Hildburghausen got the rest – the winery of Behrungen, the estate of Milz and the Echter properties. With the rearrangement of the Ernestine duchies in 1826, all the territories of the former Duchy of Saxe- Römhild were solely concentrated in the Duchy of Saxe-Meiningen.
|
|
Triethyl orthoacetate is the ethyl orthoester of acetic acid. It is also known as 1,1,1-triethoxyethane, and is an oily liquid with a colour that is anywhere from yellow to colorless. Triethyl orthoacetate is used in organic synthesis for the introduction of the acetate group to an alcohol. It is also used in the Johnson-Claisen rearrangement.
|
|
Oxybasis rubraSusy Fuentes-Bazan, Pertti Uotila, Thomas Borsch: A novel phylogeny-based generic classification for Chenopodium sensu lato, and a tribal rearrangement of Chenopodioideae (Chenopodiaceae). In: Willdenowia. Vol. 42, No. 1, 2012, p. 15-16.(syn. Chenopodium rubrum), common names red goosefoot or coastblite goosefoot, is a member of the genus Oxybasis, a segregate of Chenopodium (the goosefoots).
|
|
Similar to acetic anhydride, trifluoroacetic anhydride can be used as a dehydrating agent and as an activator for the Pummerer rearrangement. It can be used in place of oxalyl chloride in the Swern oxidation, allowing temperatures up to −30 °C. With sodium iodide, it reduces sulfoxides to sulfides. Trifluoroacetic anhydride is the recommended desiccant for trifluoroacetic acid.
|
|
Part of chromosome 9 breaks off and attaches itself to chromosome 22, facilitating exchange of genetic material between chromosomes 9 and 22. The rearrangement of the chromosomes changes the positions and functions of certain genes, which causes uncontrolled cell growth. Chronic lymphocytic leukemia (CLL) is another form of chronic leukemia, but is extremely rare in children.
|
|
This type of compounds has a double bond, and rotation or inversion around the double bond affords isomerization between the two states. Examples of the latter include fulgide and diarylethene. This type of compounds undergoes bond cleavage and bond creation upon irradiation with particular wavelengths of light. Still another class is the Di-pi-methane rearrangement.
|
|
Crich, D.; Natarajan, S.; Crich, J.Z. Tetrahedron 1997, 53, 7139–7158.() 650px The step shown above had a 70% yield (91% when the byproduct was converted to the Meyer-Schuster product in another step). The authors used the Meyer–Schuster rearrangement because they wanted to convert a hindered ketone to an alkene without destroying the rest of their molecule.
|
|
Steranes may be rearranged to diasteranes during diagenesis (C-27 to C-30, rearrangement at C-18 and C-19, no R at C-24). Oils from clastic source rocks tend to be rich in diasteranes. Cholesterol and its derivatives (such as progesterone, aldosterone, cortisol, and testosterone), are common examples of compounds with the cyclopentanoperhydrophenanthrene nucleus.
|
|
Solutions of hydrazoic acid dissolve many metals (e.g. zinc, iron) with liberation of hydrogen and formation of salts, which are called azides (formerly also called azoimides or hydrazoates). Hydrazoic acid may react with carbonyl derivatives, including aldehydes, ketones, and carboxylic acids, to give an amine or amide, with expulsion of nitrogen. This is called Schmidt reaction or Schmidt rearrangement.
|
|
Finally, MegaMan's theme is instead a rearrangement of the title theme used for the first three Battle Network games, used in the original Mega Man games; ProtoMan's is his trademark "whistle" theme first introduced in Mega Man 3; and Bass's is the theme introduced in Mega Man 7 when he battles with Mega Man for the first time.
|
|
UV susceptibility varies significantly between different polymers. Certain polycarbonates, polyesters and polyurethanes are highly susceptible, degrading via a Photo- Fries rearrangement. UV stabilisers absorb and dissipate the energy from UV rays as heat, typically by reversible intramolecular proton transfer. This reduces the absorption of UV rays by the polymer matrix and hence reduces the rate of weathering.
|
|
Opening of condensed chromatin by a pioneer factor to initiate transcription. The pioneer factor binds to tightly packed chromatin and causes a nucleosomal rearrangement. This new configuration allows space for other transcription factors to bind and initiate transcription. Pioneer factors can also actively affect transcription by directly opening up condensed chromatin in an ATP-independent process.
|
|
Glycation pathway via Amadori Rearrangement (in HbA1c, R is typically N-terminal valine). Imidazolones (R = CH2CH(OH)CH(OH)CH2OH) are typical glycation products. They arise by the condensation of 3-deoxyglucosone with the guanidine group of an arginine residue. Glycations occur mainly in the bloodstream to a small proportion of the absorbed simple sugars: glucose, fructose, and galactose.
|
|
The molecule can undergo a pseudorotational rearrangement called the Bartell mechanism, which is like the Berry mechanism but for a heptacoordinated system. It forms colourless crystals, which melt at 4.5 °C: the liquid range is extremely narrow, with the boiling point at 4.77 °C. The dense vapor has a mouldy, acrid odour. The molecule has D5h symmetry.
|
|
The proposal was for a budget hotel using the stores and terraces with new construction at the rear. The new development took place in 1988 and the Harbour Rocks Hotel was opened in 1989. Since then changes for disabled access, the rearrangement of the restaurant and bar areas and the provision of balconies at the rear have occurred.
|
|
NaDMSO condenses with esters (1) to form β-ketosulfoxides (2), which can be useful intermediates. Reduction of β-ketosulfoxides with aluminium amalgam gives methyl ketones (3). Reaction with alkyl halides followed by elimination gives α,β-unsaturated ketones (4). β-ketosulfoxides can also be used in the Pummerer rearrangement to introduce nucleophiles alpha to a carbonyl (5).
|
|
Fred Warren McLafferty is an American chemist known for his work in mass spectrometry. He is best known for the McLafferty rearrangement reaction that was observed with mass spectrometry. With Roland Gohlke, he pioneered the technique of gas chromatography-mass spectrometry. He is also known for electron capture dissociation, a method of fragmenting gas phase ions.
|
|
"Uchiage Hanabi" (, official English is "Fireworks") is a song by Daoko and Kenshi Yonezu released in August 2017. "Uchiage Hanabi" means "launching fireworks". The song is used for the 2017 anime film Fireworks and the album Thank You Blue. There are two solo versions, Yonezu's solo version, released in November in Bootleg, is a minimalist rearrangement.
|
|
Greater than 90% of cases contain a clonal rearrangement of the T-cell receptor. Oncogenic potential is conferred by upregulation of a tyrosine kinase gene on chromosome 2. Several different translocations involving this gene have been identified in cases of this lymphoma. The most common is a chromosomal translocation involving the nucleophosmin gene on chromosome 5.
|
|
All reaction steps are reversible except for the Mumm rearrangement, which drives the whole reaction sequence. In the related Passerini reaction (lacking the amine) the isocyanide reacts directly with the carbonyl group but other aspects of the reaction are the same. This reaction can take place concurrently with the Ugi reaction, acting as a source of impurities.
|
|
800px left Four years later some unrelated authors cited a skeletal rearrangement accounts for this. Diagram Notice that they are not only interested in ethers, but nitrogen containing Nu's ("TRODAT") The metal is called "Technetium" and is bound by a chelating agent. The authors state that at first the acid is halogenated, the amide is prepared, and reduced.
|
|
Methoxyketamine or 2-MeO-2-deschloroketamine is a designer drug of the arylcyclohexylamine class first reported in 1963. It is an analog of ketamine in which the chlorine atom has been replaced with a methoxy group. Its synthesis by rearrangement of an amino ketone has been reported. As an arylcyclohexylamine, methoxyketamine most likely functions as an NMDA receptor antagonist.
|
|
In: J.Am.Chem.Soc. 127, Nr. 32, 2005, S. 11240–11241, Formation of laurolactam An alternative process is the photonitrosation of cyclododecane with nitrosyl chloride in the presence of anhydrous hydrogen chloride. The resulting cyclododecanone oxime is extracted with concentrated sulfuric acid and rearranged to laurolactam by heating to 160 °C. The overall yield (photonitrogenation + Beckmann rearrangement) is up to 93%.
|
|
In an interesting application of the transmetalation method, the chiral allylic stannane 1 adds to acrolein to yield the 1,5-syn diastereomer as a single stereoisomer. A subsequent sigmatropic rearrangement increased the distance between the stereocenters even further. This step was carried out en route to (±)-patulolide C.Dorling, E.K.; Thomas, E.J. Tetrahedron Lett. 1999, 40, 471.
|
|
Jakob Meisenheimer (14 June 1876 - 2 December 1934) was a German chemist. He made numerous contributions to organic chemistry, the most famous being his proposed structure for a group of compounds now named Meisenheimer complex. He also proposed the mechanism of the Beckmann rearrangement. Later in his career, he reported the synthesis of the pyridine-N-oxide.
|
|
CIITA is a human gene which encodes a protein called the class II, major histocompatibility complex, transactivator. Mutations in this gene are responsible for the bare lymphocyte syndrome in which the immune system is severely compromised and cannot effectively fight infection. Chromosomal rearrangement of CIITA is involved in the pathogenesis of Hodgkin lymphoma and primary mediastinal B cell lymphoma.
|
|
The Corel Centre was still available but cannot be used on such short notice. The draft was instead held at the Westin Hotel in Ottawa, Ontario. The Senators were compensated by hosting the 2008 draft instead. As a result of the rearrangement, the draft was not open to the public, for the first time since 1980.
|
|
Primary and secondary brain injuries identify the processes involved, while focal and diffuse brain injury describe the severity and localization. Recent research has demonstrated that neuroplasticity, which allows the brain to reorganize itself by forming new neural connections throughout life, provides for rearrangement of its workings. This allows the brain to compensate for injury and disease.
|
|
In this case, there is significant rearrangement of the whole actin-myosin cytoskeleton and loss of E-cadherin intercellular contacts. During carcinogenesis, epithelial cells are subjected to a morphological transformation that is phenotypically similar to EMT but develops in the absence of the relevant HGF ligand. This transformation in malignant tumors can be induced by transfection of various oncogenes.
|
|
Diamantane can be prepared by Lewis acid catalyzed rearrangements of various pentacyclic tetradecanes. The best yield (84%) can obtained from trans-tetrahydro-Binor-S. A convenient synthetic procedure involves rearrangement of a hydrogenated Binor-S compound, which gives diamantane in ~70% yield. Other more highly strained precursors give diamantane in lower yield (1-47%) owing to disproportionation.
|
|
Successful beta-selection requires that TCRβ is produced, TCRβ is capable of pairing with pre-Tα to generate the pre-TCR, and that the pre-TCR can interact on the cell surface with the TCR signalling proteins. Following β-selection thymocytes generate CD4+CD8+ double positive cells, which then undergo TCRα rearrangement, resulting in completely assembled TCR.
|
|
Chromium(II) acetate has few practical applications. It has been used to dehalogenate organic compounds such as α-bromoketones and chlorohydrins. The reactions appear to proceed via 1e− steps, and rearrangement products are sometimes observed. Because the compound is a good reducing agent, it will reduce the O2 found in air and can be used as an oxygen scrubber.
|
|
Any stereochemistry set up by the oxymercuration step is scrambled by the demercuration step, so that the hydrogen and hydroxy group may be cis or trans from each other. Oxymercuration reduction is a popular laboratory technique to achieve alkene hydration with Markovnikov selectivity while avoiding carbocation intermediates and thus the rearrangement which can lead to complex product mixtures.
|
|
Carruthers, Some Modern Methods of Organic Synthesis, Cambridge University Press, Cambridge, UK, 1971, 81–90. () It should not be confused with the Wittig rearrangement. Wittig reactions are most commonly used to couple aldehydes and ketones to singly-substituted triphenylphosphonium ylides. For the reaction with aldehydes, the double bond geometry is readily predicted based on the nature of the ylide.
|
|
The Republic of India was constituted in 1947 as a union of states. After the States Reorganisation Act of 1956, there was a rearrangement of state boundaries along linguistic lines, and many states were given names in their own languages. Many states are named due to their geographical characteristics, peculiar history or populations and colonial influences.
|
|
It has become a classic reaction in organic synthesis and has been reviewed many times before. It can be viewed as an intramolecular disproportionation reaction, as one carbon center is oxidized while the other is reduced. Scheme 1. Benzilic acid rearrangement The reaction has been shown to work in aromatic, semi-aromatic, aliphatic, and heterocyclic substrates.
|
|
Mutations in this gene have been associated with thyroid dysgenesis, thyroid follicular carcinomas and atypical follicular thyroid adenomas. PAX8/PPARy rearrangement account for 30-40% of conventional type follicular carcinomas., and less than 5% of oncocytic carcinomas (aka Hurthle-Cell Neoplasms). Expression of PAX8 is increased in neoplastic renal tissues, Wilms tumors, ovarian cancer and Müllerian carcinomas.
|
|
In response to criticism of the DH.34's high landing speed, full-span flaps were fitted. To reduce the hazards of ditching, the undercarriage could be jettisoned and the fuselage was made watertight. Passengers sat in four rows of seats, singles on the left and doubles on the right. A rearrangement of luggage space allowed room for toilets.
|
|
The example given below can produce simultaneous lowpass, highpass and bandpass outputs from a single input. This is a second-order (biquad) filter. Its derivation comes from rearranging a high-pass filter's transfer function, which is the ratio of two quadratic functions. The rearrangement reveals that one signal is the sum of integrated copies of another.
|
|
The abnormal cells build up in the bone marrow and prevent the development of other healthy cells. This type of arrest is still under study but in most cases, a gene inactivation or activation has occurred due to chromosome translocations or inversion. AML-M4 with an inversion of chromosome 16 is caused by breakage and rearrangement within itself.
|
|
Once the catalytic center is completed, the hydrogenase precursor undergoes a C-terminal cleavage that prompts rearrangement of its structure and association with the small subunit. Finally, the completed enzyme is transported to its correct position within the cell. Hydrogenase promoter, PSH, can be studied constructing a PSH promoter-gfp fusion by using green fluorescent protein (gfp) reporter gene.
|
|
The enriched molecules were then fragmented and purified. cDNA library is then constructed and sequencing is performed. An important additional feature is that RNA methyltransferase covalent linkage to the C5 of m-aza-C induces rearrangement and ring opening. This ring opening results in preferential pairing with cytosine and is therefore read as guanosine during sequencing.
|
|
Marie Mercury Roth (April 30, 1926 – January 3, 2020) was an American synthetic organic chemist. She was the first female Ph.D. candidate at the chemistry department of University of Wisconsin-Madison, where she worked with William Summer Johnson. She received her Doctorate of Philosophy in 1951 for the Application of the Favorskii rearrangement to the problem of angular methylation.
|
|
There is one particular reaction studied by Grutzmacher et al. that exhibits the rearrangement of coordination character of PCO. Initially when reacting the anion with triorganyl silicon compounds, it binds via the oxygen forming the kinetic oxyphosphaalkyne product. The thermodynamic silyl phosphaketene product is generated when the kinetic product rearranges to allow PCO to coordinate through phosphorus.
|
|
In 2005, the IMA building and grounds underwent an extensive renovation, which included rearrangement of the outdoor sculpture collection. The numbers were moved to their second and current location during this time. Indiana designed the presentation of the sculptures, arranging them in pairs of personal significance which he detailed in a 2003 drawing.Indianapolis Museum of Art.
|
|
Pericyclic reactions, the SN2 reaction, and some rearrangements - such as the Claisen rearrangement - are concerted reactions. The rate of the SN2 reaction is second order overall due to the reaction being bimolecular (i.e. there are two molecular species involved in the rate- determining step). The reaction does not have any intermediate steps, only a transition state.
|
|
Following Deputy Prime Minister Barnaby Joyce's resignation from cabinet, the fifth rearrangement of the Second Turnbull Ministry was sworn in on 26 February 2018 by the Governor of Victoria, Linda Dessau, in her capacity as Administrator of the Commonwealth while Governor-General Sir Peter Cosgrove was overseas. Michael McCormack took on Joyce's roles after being elected National Party leader that morning. Rearrangement of other portfolios took effect from 5 March 2018 when the Governor-General Sir Peter Cosgrove swore in the newly appointed Ministers and Parliamentary Secretaries: Darren Chester as Minister for Veterans’ Affairs and Minister for Defence Personnel; Keith Pitt as Assistant Minister to the Deputy Prime Minister; and Mark Coulton as Assistant Minister to the Minister for Trade, Tourism and Investment. Damian Drum and Luke Hartsuyker were demoted from the ministry.
|
|
Thomas is initially reluctant to take her up on the offer, knowing that his adopted family would be disappointed as it was the ministry who they blamed for the loss of their mother and wife. Thomas is won over and accepts the job when Diana tells him that his family need not know of his true occupation and that they would be granted immunity from ever being rearranged again. Shortly after joining the Ministry, Thomas gets his first experience of participating in a rearrangement when a young girl is to be moved from sanguine territory (the red quarter) to choleric (the yellow quarter). During his time as an observer to the rearrangement, he gets his first view of a border gate, a complex of high concrete walls, barbed wire and minefields patrolled by border guards.
|
|
While Ferrier was there, Calvin was awarded the Nobel Prize for Chemistry, and he also met Carolyn Tompkins, the pair marrying in Edinburgh in 1962. Arriving in New Zealand in 1970 as Victoria University’s first Chair of Organic Chemistry, Ferrier continued to lead work on the monosaccharides, specialising in their use as starting materials for the synthesis of non-carbohydrate compounds of pharmaceutical interest. He had previously clarified the mechanism of the Fischer glycosidation and discovered an allylic rearrangement reaction of glycals, now known as the Ferrier rearrangement – the first of two reactions that bear his name. Many of Ferrier's best discoveries were made by following up unexpected chemical observations, which often led him into uncharted territory. His second ‘name’ reaction, the Ferrier carbocyclization, was the result of this approach.
|
|
All known reactions have been observed to share the same initial steps. (See Figure 2.) First, the β-thioglucoside linkage is cleaved by myrosinase, releasing D-glucose. The resulting aglycone undergoes a spontaneous Lossen-like rearrangement, releasing a sulfate. The last step in the mechanism is subject to the greatest variety depending on the physiological conditions under which the reaction takes place.
|
|
This mechanism also proceeds with inversion at the carbon center. This reaction is known to be reversible. Depending on the relative stabilities of the carbanion and oxy-anion formed, a silyl ether is perfectly capable of rearranging to a species with the silicon bonded to the carbon atom, and the free alcohol being present. This would be termed a Retro-Brook rearrangement.
|
|
Due to the shallow depths, sediments undergo only minor compaction and grain rearrangement during this stage. Organisms rework sediment near the depositional interface by burrowing, crawling, and in some cases sediment ingestion. This process can destroy sedimentary structures that were present upon deposition of the sediment. Structures such as lamination will give way to new structures associated with the activity of organisms.
|
|
The ships were designed by the firm Cavallini and were an enlarged version of the preceding . Among the changes were the introduction of a partially double hulled design, rearrangement of the ballast tanks, increases in fuel capacity and range, and a strengthening of the armament. The number of torpedoes was increased from 12 on the Settembrini class to 16.Miller, p.
|
|
According to Iranian sources, Iraqi General Maher Abd al-Rashid had described the unit as a "black scorpion" that should be destroyed,25th Karbala Division farsnews.com possibly a reference to their black frogman suits during the operation. The division was merged with the Basij of Mazandaran Province to form the Mazandaran Karbala Provincial Corps during the rearrangement of the IRGC units in 2008.
|
|
The two largest macrochromosome pairs as well as the Z (female) chromosome are submetacentric, while the third-largest chromosome pair is acrocentric and the fourth-largest is metacentric. The W chromosomes are acrocentric too, as are the larger microchromosomes, the smaller ones probably being telocentric. Compared to the greylag goose, there seems to have been some rearrangement on the fourth-largest chromosome pair.
|
|
The album consists of only one previously released single, coconuts feat. kokomo. Several songs such asHitomi Sorasanaide received new version and instrumentation under title 2009+Ukulele Style; Gekkou no Nagisa and Blue eyes had received new rearrangement from the original version as well. Two tracks out of twelve are instrumental. The band covered Anzen Chitai's 12th single Natsu no Owari no Harmony.
|
|
Since the rearrangement of the townships in North Rhine-Westphalia in 1975, Eissen is no more an independent community. Eissen now belongs to the municipal area of Willebadessen and is represented on city council by one direct member. Since the last local election in September 2004, three people from Eissen are members of the city council (CDU: 2, SPD:1).
|
|
Weerman degradation, also named Weerman reaction, is a name reaction in organic chemistry. It is named after Rudolf Adrian Weerman, who discovered it in 1910. In general, it is an organic reaction in carbohydrate chemistry in which amides are degraded by sodium hypochlorite, forming an aldehyde with one less carbon. Some have regarded it as an extension of the Hofmann rearrangement.
|
|
Steviol is a diterpene first isolated from the plant Stevia rebaudiana in 1931. Its chemical structure was not fully elucidated until 1960. Steviol occurs in the plant as steviol glycosides, sweet compounds that have found widespread use as sugar substitutes. The aglycon is prepared by enzymatic hydrolysis, since upon acid treatment steviol will undergo Wagner-Meerwein rearrangement to the very stable isosteviol.
|
|
Carpet tiles are also available, typically square. These are usually only used in commercial settings and are affixed using a special pressure-sensitive glue, which holds them into place while allowing easy removal (in an office environment, for example) or to allow rearrangement in order to spread wear.Fletcher, Alan J. The Complete Carpet Buying Guide. Portland Oregon: AJ Books 2006.
|
|
Large-scale application McIntosh et al. used an allylic diazene rearrangement in their synthesis of the C21–C34 fragment of antascomicin B. The hydrazone was reduced selectively with catecholborane and excess reducing agent decomposed with sodium thiosulfate. The crude reaction product was then treated with sodium acetate and heated under reflux in chloroform to give the 1,4-syn isomer. Scheme 22.
|
|
In this Paterno–Büchi reaction, a photoexcited carbonyl group is added to an unexcited olefin, yielding an oxetane. In photochemical reactions, atoms and molecules absorb energy (photons) of the illumination light and convert into an excited state. They can then release this energy by breaking chemical bonds, thereby producing radicals. Photochemical reactions include hydrogen–oxygen reactions, radical polymerization, chain reactions and rearrangement reactions.
|
|
750px Further reaction improvement came when Hudlicky and Brown proved that vinylcyclopropane rearrangements are amenable to transition metal catalysts. Using a Rh(I) acetate catalyst they were able to promote rearrangements from room temperature to 80 °C. 750px Analogous to the rate acceleration observed in the anionic-oxy-Cope rearrangement Danheiser reported a very similar effect for vinylcyclopropane substrates bearing [alkoxy] substituents.
|
|
Five member analogues to the above substituted reagents enlarge under TDR conditions. Alkyl substitutions as opposed to aryl substitutions result in diminished TDRs. Smith and Baer assert that these observations support their mechanism. Since substitution stabilizes the carbonium ion after damnification, the resulting carbonium ion is more likely to react with a nucleophile present (water in this case) and not undergo rearrangement.
|
|
Antheraea pernyi, the Chinese (oak) tussar moth, Chinese tasar moth or temperate tussar moth, is a large moth in the family Saturniidae. The species was first described by Félix Édouard Guérin-Méneville in 1855. Antheraea roylei is an extremely close relative, and the present species might actually have evolved from ancestral A. roylei by chromosome rearrangement. They are originally from southern China.
|
|
When P-TEFb is extracted from the 7SK snRNP, 7SK RNA undergoes a conformation change, HEXIM is ejected and hnRNPs take the place of the factors removed. The re- sequestration of P-TEFb requires another rearrangement of the RNA, binding of HEXIM and then P-TEFb. In rapidly growing cells the 7SK snRNP is the predominate form of P-TEFb. For review.
|
|
The most common soil types are silicate leptosols, that belong to the thin stony soils around areas of rock and scree. In flatter areas with less rearrangement of the soil particles are stony Ranker leptosols of various thickness. One particular soil type, brown Ranker occurs above argillite rock. Podsolised brown earth soils are found around the edges of the gorge.
|
|
Region of Xp11.2 duplications. Xp11.2 duplication is a genomic variation marked by the duplication of an X chromosome region on the short arm p at position 11.2, defined by standard karyotyping (G-banding). This gene-rich, rearrangement prone region can be further divided into three loci - Xp11.21, Xp11.22 and Xp11.23. The duplication could involve any combination of these three loci.
|
|
It was also mandated by the Construction Department that the new ships have armor protection equal or superior to Von der Tanns and a top speed of at least . During the design process, there were many weight increases due to growth in the size of the citadel, armor thickness, additions to the ammunition stores, and the rearrangement of the boiler system.
|
|
Graphite is based on the TrueType font format, and adds three of its own tables. It allows for a variety of rendering rules, including ligatures, glyph substitution, glyph insertion, glyph rearrangement, anchoring diacritics, kerning, and justification. Graphite rules may be sensitive to the context. For instance, there might be a glyph substitution rule that replaces every non-final s by an ſ.
|
|
This hypothesis was motivated by the well known santonin-desmotroposantonin rearrangement of steroid dienones into aromatic compounds. It is now accepted that (+)-totarol is synthesized biologically from ferruginol. Geranyl geranyl pyrophosphate 4 undergoes typical diterpene cyclization to form (−)-abietadiene 5, which is oxidized to form ferruginol 3, which proceeds through a spiro intermediate to form (+)-totarol (Scheme 2). Scheme 2.
|
|
The film was officially announced by GDH at a press event on 20 April 2017, along with the release of its theme song "Mong Chan Tee" (, which translates as "Look at Me"). Performed by Suthita Chanachaisuwan, the song is a rearrangement of the song "Why Can't You See" by Thai indie pop band Fwends, with new lyrics by Apiwat Eurthavornsuk.
|
|
A classic laboratory organic synthesis for carbazole is the Borsche–Drechsel cyclization. Borsche–Drechsel synthesis In the first step, phenylhydrazine is condensed with cyclohexanone to the corresponding imine. The second step is a hydrochloric acid-catalyzed rearrangement reaction and ring-closing reaction to tetrahydrocarbazole. In one modification, both steps are rolled into one by carrying out the reaction in acetic acid.
|
|
The metal ion-catalyzed σ-bond rearrangement is a collection of chemical reactions that occur with highly strained organic compounds are treated with metal ions like Ag+, Rh(I), or Pd(II) based reagents.Michael B. Smith, Jerry March, March's Advanced Organic Chemistry, 5th Ed., John Wiley & Sons, Inc., 2001, p. 1459. [2+2] ring openings are sometimes observed: :Scheme 1.
|
|
As a structural analogue of 2-oxazolines, 2-imidazolines have been developed as ligands in coordination chemistry. The substitutions on the nitrogen atom in the imidazoline ring provide opportunities for fine-tuning the electronic and steric properties. Some of the complexes function as catalysts for Suzuki–Miyaura couplings, Mizoroki–Heck reactions, Diels–Alder reactions, asymmetric allylic substitution, [3,3] sigmatropic rearrangement, Henry reactions, etc.
|
|
Adapted from Methyl shifts to the vinyl cation. Adapted from Methyl shifts are observed in the addition of tert-butyl cation to but-2-yne. The pentaallyl cation that is formed could be the result of a single 1,3-methyl shift or two consecutive 1,2-metyl shifts. Rearrangement via the double bond could also change the size of a cyclic system.
|
|
"Every Night" () is a song recorded by South Korean girl group EXID. The song was released as a digital single on October 2, 2012 through AB Entertainment. The song is written by member LE, and co-produced by LE and Shinsadong Tiger. "Every Night" is a rearrangement of the track "Call", which was on their first extended play, Hippity Hop.
|
|
After the revolt's failure, David was forced to make Basil the legatee of his extensive possessions. In 1001, after the death of David of Tao, Basil inherited Tao, Phasiane, and Speri. These provinces were then organized into the theme of Iberia with the capital at Theodosiopolis. This forced the successor Georgian Bagratid ruler Bagrat III to recognize the new rearrangement.
|
|
Friedman, pp. 40-41 These modifications changed not only the boats' appearance, but also their terminology: After a GUPPY conversion, the faired structure around the boat's conning tower and mast supports was called the "sail". Internally, the boats underwent considerable rearrangement to accommodate larger battery wells and batteries of greatly increased electrical power. The batteries were of a new design.
|
|
She worked with David MacMillan and earned her master's degree in 2000. She joined California Institute of Technology for her PhD, working on the Zwitterionic Claisen Rearrangement and the total synthesis of Erythronolide B. Dong was appointed a National Institutes of Health postdoctoral fellow at UC Berkeley College of Chemistry, working on supramolecular chemistry with Robert G. Bergman and Ken Raymond.
|
|
The Boekelheide reaction is a rearrangement of α-picoline-N-oxides to hydroxymethylpyridines. It is named after Virgil Boekelheide who first reported it in 1954. Originally the reaction was carried out using acetic anhydride, which typically required a period at reflux (~140°C). The reaction can be performed using trifluoroacetic anhydride (TFAA), which often allows for a room temperature reaction.
|
|
Three years later, when Labour won the 1984 elections, Goff was elevated to Cabinet, becoming its youngest member. He served as Minister of Housing and Minister of Employment. After the 1987 elections, Goff dropped the Housing portfolio, but also became Minister of Youth Affairs and Minister of Tourism. Later, after a significant rearrangement of responsibilities, Goff became Minister of Education.
|
|
In this century is also produced the Codex Calixtinus, the medieval Jacobean history strongpoint. Two centuries later the archbishop Berenguel of Landoira, after an urban revolt in Santiago, developed a second work of rearrangement, upon the same base of selection, ordainment, documentation organization and copy to new supports. Thus, were produced the Tumbo B and C, with royal documentation, pontifical, ecclesiastic and civilian.
|
|
Other linked genes include hereditary prostate cancer gene 1 (HPC1), the androgen receptor, and the vitamin D receptor. TMPRSS2-ETS gene family fusion, specifically TMPRSS2-ERG or TMPRSS2-ETV1/4 promotes cancer cell growth. These fusions can arise via complex rearrangement chains called chromoplexy. Two large genome-wide association studies linked single-nucleotide polymorphisms (SNPs) to prostate cancer in 2008.
|
|
However, due to the ensuing strings of wars, it was completed only in 1922. Today, Stari Dvor serves as the Belgrade City Hall, while Novi Dvor hosts the Presidency of Serbia. Under the mayor Ljubomir Davidović, the Technical Administration of Belgrade Municipality organized architectural design competition for complete rearrangement of Terazije in March 1911. Stipulations included removal of the fountain.
|
|
Montgomery, E., S.M. Huang, C.H. Langley, and B.H. Judd. 1991. Chromosome rearrangement by ectopic recombination in drosophila melanogaster: genome structure and evolution. Genetics 129: 1085-1098 It occurs relatively frequently—in at least one yeast species (Saccharomyces cerevisiae) the frequency of ectopic recombination is roughly on par with that of allelic (or traditional) recombination.Licthen, M, R.H. Borts, and J.E. Haber. 1986.
|
|
Aman Doktor (Oh! Doctor) is Candan Erçetin's seventh studio album. It released in 2005, around the tenth year of the singer's public career. The album is a compilation and partial rearrangement of popular folk songs common to Turkish and Greek cultures, sung in both languages, and represents a culmination of the efforts of Erçetin as a friendship envoy to these two countries.
|
|
KMT2A (formerly MLL) gene rearrangements are most common and occur in the embryo or fetus before birth. These rearrangements result in increased expression of blood cell development genes by promoting gene transcription and through epigenetic changes. In contrast to childhood ALL, environmental factors are not thought to play a significant role. Aside from the KMT2A rearrangement, only one extra mutation is typically found.
|
|
The mechanism of oxidation of -CH2C(O)R group by SeO2 has been well investigated. The oxidation of carbonyl alpha methylene positions begins with attack by the enol tautomer at the electrophilic selenium center. Following rearrangement and loss of water, a second equivalent of water attacks the alpha position. Selenic acid is liberated in the final step to give the 1,2-dicarbonyl product.
|
|
In the Government of Australia, the Minister for Defence Personnel is the Hon. Darren Chester , in office since 5 March 2018. Chester also serves as the Minister for Veterans' Affairs and the Minister Assisting the Prime Minister for the Centenary of ANZAC following a rearrangement in the second Turnbull Ministry. The ministerial portfolio has existed under various names since 1987.
|
|
Retrieved on 2015-06-28. Woods wins big in Heptathlon at US Junior Champs - Day TWO. IAAF (2006-06-24). Retrieved on 2015-06-28. Bad weather including heavy storms caused a rearrangement of the programme, with many events scheduled on the first day being postponed. The weather also affected the calibre of performances at the meeting.Dunaway, James (2006-06-23).
|
|
The oxyallyl diradical (OXA) is a trimethylenemethane molecule with one methylene group replaced by oxygen. This reactive intermediate is postulated to occur in ring opening of cyclopropanones, allene oxides and in the Favorskii rearrangement. The intermediate has been produced by reaction of oxygen radical anions with acetone and studied by photoelectron spectroscopy. The experimental electron affinity of OXA is 1.94 eV.
|
|
At the early stage of lymphocyte B development, loci of immunoglobulins are rearranged. During rearrangement, segment VH on heavy chain locus is connected with one DH segment, then V-D group is combined with JH segment. Eventually, exon with open reading frame coding segments: VH, DH, JH of immunoglobulin. Through RNA splicing during transcription, this exon becomes connected to exon for CH segment.
|
|
McKenna and Davies found that 10 mM or greater HClO is necessary to fragment proteins in vivo. Consistent with these results, it was later proposed that the chloramine undergoes a molecular rearrangement, releasing HCl and ammonia to form an aldehyde. The aldehyde group can further react with another amino group to form a Schiff base, causing cross-linking and aggregation of proteins.
|
|
It falls a substantial distance from Dryandra, suggesting that similarities between those two groups are indeed superficial. Early in 2007, Mast and Thiele initiated a rearrangement of Banksia by merging Dryandra into it, and publishing B. subg. Spathulatae for the species having spoon-shaped cotyledons. They foreshadowed publishing a full arrangement once DNA sampling of Dryandra was complete; in the meantime, B. subg.
|
|
The west wing however appears to have undergone more change and ad hoc rearrangement of the walls. The east wing retains much of the original layout and fabric. Door handles to the east wing are a distinctive lever type while those to the west wing are plain, stainless steel knob-sets. The toilets in the east wing are largely in original condition.
|
|
Favorsky studied chemistry at the imperial University of Saint Petersburg from 1878 to 1882. He joined Alexander Butlerov's laboratory for several years, and in 1891 became a lecturer. In 1895, Favorksy received his PhD and became professor for technical chemistry. His discovery of the Favorskii rearrangement in 1894 and the Favorskii reaction between 1900 and 1905 are connected to his name.
|
|
"Lay Down" is a re-recorded version of the hit single from Bursting at the Seams. "Sealed With a Traitor's Kiss" is a rearrangement of a track which appears on 1978 studio album Deadlines. The bonus track is the original 1979 version - also released as a single - of a track which later appeared on the 1991 studio album Ringing Down the Years.
|
|
Maersk Air commenced services from Billund to Frankfurt in 1993,Ellemose: 107 and a year later it started flights from Copenhagen to Kristiansand.Ellemose: 293 To meet the upcoming deregulation, Maersk carried out a major fleet rearrangement in 1993. The airline sold its Fokker 50s and leased them back. Meanwhile, it procured six Boeing 737-500s, which were delivered in 1996.
|
|
This clade is however, not particularly close to the clade that corresponds to B. ser. Ochraceae. Early in 2007 Mast and Thiele initiated a rearrangement of Banksia by transferring Dryandra into it, and publishing B. subg. Spathulatae for the species having spoon-shaped cotyledons; in this way they also redefined the autonym B. subg. Banksia. All members of B. ser.
|
|
Its merit is that it may account for the fact that chromoplexy appears to cause DNA breaks in regions of the nucleus that are actively transcribed and correspond to open chromatin. It also may explain how DNA from multiple chromosomes may be involved in a single complex rearrangement due to the nuclear co-localization of genes from multiple chromosomes at transcription hubs.
|
|
Blue dashed lines indicate a σ bond being broken, red dashed lines indicate a σ bond being formed. Significantly, these stereochemical experiments imply that the cationic 2-aza- Cope rearrangement (as well as Mannich cyclization) occur faster than enol or iminium tautomerization. If they were not, no meaningful stereochemistry would have been observed, highlighting the facility of this fast reaction.
|
|
The museum is located in a neo-classical building in 30 Kronprinsessegade in central Copenhagen, overlooking Rosenborg Castle Garden. From 2006 to 2009 the collection was closed to the public while the premises underwent a major refurbishment and rearrangement. When it reopened on 15 May 2009, it was described as "the most exclusive museum in Denmark" in national Danish newspaper Politiken.
|
|
A rearrangement in TNNT1 gene (c.574_577 delins TAGTGCTGT) leading to aberrant splicing that causes C-terminal truncation of the protein (L203 truncation) was reported in 9 Palestinian patients from 7 unrelated families with recessively inherited nemaline Myopathy. Illustrated in Fig. 3, the S108X mutation truncates ssTnT protein to cause a loss of functional structures equivalent to that of E180X.
|
|
Methler is a part of Kamen since January 1, 1968. It was an independent commune until the first level of the communal rearrangement in 1967. After that, it was merged along with the communes Westick and Wasserkurl to the commune Methler. Several archaeological founds in Westick indicate that there was Roman colonisation long before the name "Methler" was first established in 898 AD.
|
|
Classically, aromatization reactions involve changing the C:H ratio of a substrate. When applied to cyclopentadiene, proton removal gives the aromatic conjugate base cyclopentadienyl anion, isolable as sodium cyclopentadienide: :2 Na + 2 C5H6 -> 2 NaC5H5 \+ H2 Aromatization can entail removal of hydride. Tropylium, arises by the aromatization reaction of cycloheptatriene with hydride acceptors. : + → + + Ciamician-Dennstedt rearrangement of a pyrrole to a pyridine.
|
|
Williams, R. V., Chem. Rev. 2001, 101 (5), 1185–1204. A representative illustration of the transition state of the Cope rearrangement of the electronically neutral hexa-1,5-diene is presented below. Here one can see that the two π-bonds are breaking while two new π-bonds are forming, and simultaneously the σ-bond is breaking while a new σ-bond is forming.
|
|
The mechanism of pore formation of perfingolysin O (PFO; TC# 1.C.12.1.1), which is secreted by Clostridium perfringens, begins with encountering and binding to cholesterol on the target membrane. The C-terminus of PFO domain 4 (D4) encounters the membrane first. The binding of D4 triggers a structural rearrangement in which the PFO monomers oligomerize forming the pre-pore complex.
|
|
Lipscomb's group also achieved an understanding of it through electron orbital calculations using formulas by Edmiston and Ruedenberg and by Boys. The Eberhardt, Crawford, and Lipscomb paper discussed above also devised the "styx number" method to catalog certain kinds of boron-hydride bonding configurations. Diamond-square-diamond (DSD) rearrangement. At each vertex is a boron atom and (not shown) a hydrogen atom.
|
|
The more common 1,3,5-isomers are prepared by trimerization of nitrile and cyanide compounds, although more specialized methods are known. The 1,2,3- and 1,2,4-Triazines are more specialized methods. The former family of triazines can be synthesized by thermal rearrangement of 2-azidocyclopropenes. Also mainly of specialized interest, the 1,2,4-isomer is prepared from condensation of 1,2-dicarbonyl compounds with amidrazones.
|
|
Paquette’s honors include Sloan Fellow, Guggenheim Fellow, ACS Award for Creative Work in Synthetic Organic Chemistry, and the Arthur C. Cope Scholar Award of the ACS. Professor Paquette’s career has resulted in contributions to numerous areas in the field of organic chemistry, including synthesis and properties of unusual molecules, natural products total synthesis, synthetic methodology, rearrangement processes, and stereoelectronic control.
|
|
As the recording indicates, Dylan had difficulty fitting the words to the tempo, and evidently this led to its rearrangement, as heard on Blonde on Blonde, in a more "rock"-oriented 4/4 time. A live version of this song appears on the 1976 album Hard Rain, and was also released as a single with "Rita May" as the B-side.
|
|
Hydroxamic acids are usually prepared from either esters or acid chlorides by a reaction with hydroxylamine salts. For the synthesis of benzohydroxamic acid, the overall equation is: :C6H5CO2Me + NH2OH → C6H5C(O)NHOH + MeOH Hydroxamic acids can also be synthesized from aldehydes and N-sulfonylhydroxylamine via the Angeli-Rimini reaction. A well- known reaction of hydroxamic acid esters is the Lossen rearrangement.
|
|
A technique for protein sequences has been implemented in the software program SAGA (Sequence Alignment by Genetic Algorithm) and its equivalent in RNA is called RAGA. The technique of simulated annealing, by which an existing MSA produced by another method is refined by a series of rearrangements designed to find better regions of alignment space than the one the input alignment already occupies. Like the genetic algorithm method, simulated annealing maximizes an objective function like the sum-of-pairs function. Simulated annealing uses a metaphorical "temperature factor" that determines the rate at which rearrangements proceed and the likelihood of each rearrangement; typical usage alternates periods of high rearrangement rates with relatively low likelihood (to explore more distant regions of alignment space) with periods of lower rates and higher likelihoods to more thoroughly explore local minima near the newly "colonized" regions.
|
|
In August 1949, the company finally proposed to cut 10% of wages and cut retirement pay in half. As a result, the company promised not to dismiss employees, instead of accepting a 10% wage reduction. Under this circumstance, the other car companies laid down their workforce. For example, at Nihon Denso (currently Denso), which was established in December 1949, a labor dispute arose over personnel rearrangement.
|
|
Second, regardless of the reaction mechanism, the rearrangement gives a ketene intermediate, which can be trapped by a weakly acidic nucleophile, such as an alcohol or amine, to give the corresponding ester or amide, or an olefin, to give a [2+2] cycloaddition adduct. Strong acids do not rearrange, but rather protonate the α-carbon and give SN2 products. Concerted versus stepwise mechanism for ground state conformers.
|
|
These three properties are as follows: # the nature of the subunits of the multimeric protein are such that they are identical to each other # ligand binding induces a conformational change in the protein # the conformational change is an intramolecular rearrangement within the protein The i3 nature of a multimeric, cooperatively-acting protein is useful in standardizing the structural and physical basis of the sequential model.
|
|
Most of the enzymes have not been characterized and there may be several more intermediates that are still unknown. However, what is known is that averufin is oxidized by a P450-oxidase, AvfA, in a Baeyer-Villiger oxidation. This opens the ether rings and upon rearrangement versiconal acetate is formed. Now an esterase, EstA, catalyzes the hydrolysis of the acetyl, forming the primary alcohol in versiconal.
|
|
The following scheme describes the interconversion between an aldose and a ketose, where R is any organic residue. 700px The equilibrium or the reactant to product ratio depends on concentration, solvent, pH and temperature. At equilibrium the aldose and ketose form a mixture which in the case of the glyceraldehyde and dihydroxyacetone is also called glycerose. A related reaction is the alpha-ketol rearrangement.
|
|
The Beckmann fragmentation is a reaction that frequently competes with the Beckmann rearrangement. When the group α to the oxime is capable of stabilizing carbocation formation, the fragmentation becomes a viable reaction pathway. The reaction generates a nitrile and a carbocation, which is quickly intercepted to form a variety of products. The nitrile can also be hydrolyzed under reaction conditions to give carboxylic acids.
|
|
This gene encodes one of the immunoglobulin lambda-like polypeptides. It is located within the immunoglobulin lambda locus but it does not require somatic rearrangement for expression. The first exon of this gene is unrelated to immunoglobulin variable genes; the second and third exons are the immunoglobulin lambda joining 1 and the immunoglobulin lambda constant 1 gene segments. Alternative splicing results in multiple transcript variants.
|
|
U.S.S.R. (in press) The change from a spreading plate boundary to a subduction plate boundary may result from rapid rearrangement of relative plate motion. A transform fault may also become a subduction zone, with the side with the higher, hotter, thinner lithosphere riding over the lower, colder lithosphere. This mechanism would lead to obduction of ophiolite complex if it occurred near a continental margin.
|
|
Metalation of allyl ether with alkyllithium or LDA forms an anion α to the oxygen, and can proceed to 2,3-Wittig rearrangement. Addition of donor ligands such as TMEDA and HMPA can increase metalation rate and broaden substrate scope. Chiral organolithium reagents can be accessed through asymmetric metalation. :center Directed ortho metalation is an important tool in the synthesis of regiospecific substituted aromatic compounds.
|
|
The rubble was partially used for burying the marsh in Bara Venecija, where the Belgrade Main railway station was built. When the square was renovated in 1928–1929, the remains of the Stambol Gate's foundations were discovered beneath the pavement, but it was not recorded whether the remains were dug up again or were removed. Additional remains were found in 1949, during another rearrangement of the square.
|
|
However, flash vacuum pyrolysis at 500 °C leads to loss of molecular nitrogen (N) leaving a three-member aziridine ring. Certain triazoles are relatively easy to cleave due to ring–chain tautomerism. One manifestation is found in the Dimroth rearrangement. 1,2,3-Triazole finds use in research as a bioisostere in medicinal chemistry building block for more complex chemical compounds, including pharmaceutical drugs such as mubritinib and tazobactam.
|
|
In order to generate bilobalide, C20 ginkgolide 13 must form first. To transform from GGPP to abietenyl cation 5, a single bifunctional enzyme abietadiene synthase E1 is required. However, due to the complexity of ginkgolide structures for rearrangement, ring cleavage, and formation of lactone rings, diterpene 8 is used to explain instead. Levopimaradiene 6 and abietatriene 7 are precursors for ginkgolide and bilobalide formation.
|
|
The clade is not very well resolved, however, having a number of polytomies: Early in 2007 Mast and Thiele initiated a rearrangement of Banksia by transferring Dryandra into it, and publishing B. subg. Spathulatae for the species having spoon-shaped cotyledons; in this way they also redefined the autonym B. subg. Banksia as containing those taxa lacking spoon-shaped cotyledons. The members of B. ser.
|
|
Early in 2007, Mast and Thiele initiated a rearrangement of Banksia by merging Dryandra into it, and publishing B. subg. Spathulatae for the species having spoon-shaped cotyledons. They foreshadowed publishing a full arrangement once DNA sampling of Dryandra was complete; in the meantime, if Mast and Thiele's nomenclatural changes are taken as an interim arrangement, then B. spinulosa var. spinulosa is placed in B. subg. Spathulatae.
|
|
CD19 is widely expressed during all phases of B cell development until terminal differentiation into plasma cells. During B cell lymphopoiesis, CD19 surface expression starts during immunoglobulin (Ig) gene rearrangement, which coincides during B lineage commitment from hematopoietic stem cell. Throughout development, the surface density of CD19 is highly regulated. CD19 expression in mature B cells is threefold higher than that in immature B cells.
|
|
Since viscosity is the resistance to thermally activated plastic deformation, a viscous material will lose energy through a loading cycle. Plastic deformation results in lost energy, which is uncharacteristic of a purely elastic material's reaction to a loading cycle. Specifically, viscoelasticity is a molecular rearrangement. When a stress is applied to a viscoelastic material such as a polymer, parts of the long polymer chain change positions.
|
|
Moret is the author of The Theory of Computation (Addison-Wesley, 1998). With H. D. Shapiro, he is the co-author of Algorithms from P to NP, Volume I: Design and Efficiency (Benjamin Cummings, 1991). He has also written many highly cited research papers in bioinformatics, including papers on calculating the minimum genetic rearrangement distance between a pair of related genomes. and on evolutionary tree reconstruction...
|
|
Non-coding RNAs such as short-interspersed nuclear elements, which have been known to associate with and contribute to chromatin structure, can thus play huge role in regulating gene expression. Short-interspersed-nuclear-elements similarly can be involved in gene regulation by modifying genomic architecture. In fact Usmanova et al. 2008 suggested that short-interspersed nuclear elements can serve as direct signals in chromatin rearrangement and structure.
|
|
Following the rearrangement, the drugged glass ends up with Bryan, who quickly drinks it all. Jack arrives at the table and switches glasses, unaware that Bryan had already ingested the drops. While Jack and Dina reconnect, Marc blackmails Hayley by threatening to tell Roberto they had sex three weeks earlier. Hayley once again asks Jack to handle him, so Jack and Sidney lock Marc in a cupboard.
|
|
Zn(II) salts) or a Brønsted acid catalyst using the anhydride or even the carboxylic acid itself as the acylation agent. :400x400px If desired, the resulting ketone can be subsequently reduced to the corresponding alkane substituent by either Wolff–Kishner reduction or Clemmensen reduction. The net result is the same as the Friedel–Crafts alkylation except that rearrangement is not possible.Friedel-Crafts Acylation. Organic-chemistry.org.
|
|
The reintroduction of the pyrophosphate group to the cation produces GPP isomer, known as linalyl pyrophosphate (LPP). LPP then forms a resonance-stable cation by losing its pyrophosphate group. Cyclization is then completed thanks to this more favorable stereochemistry of the LPP cation, now yielding a terpinyl cation. Finally, a 1,2-hydride shift via a Wagner-Meerwein rearrangement produces the terpinen-4-yl cation.
|
|
T-cell antibodies bind to antigens such as virus infected cells or tumor cells. In Lutzner cells, there is a mutation in the T-cell receptor that inhibits antigens like CD8 and CD7, but stimulates the over production of other antigens like CD4. This mutation is a clonal gene rearrangement at the TCR-γ gene. Clonal gene rearrangements create novel or new surface antibodies during early differentiation.
|
|
In all instances only esters can be used with stable acyl components that can withstand the harsh conditions of the Fries rearrangement. If the aromatic or the acyl component is heavily substituted then the chemical yield will drop due to steric constraints. Deactivating meta-directing groups on the benzene group will also have an adverse effect as can be expected for a Friedel–Crafts acylation.
|
|
Thouless made many important contributions to the theory of many-body problems. For atomic nuclei, he cleared up the concept of 'rearrangement energy' and derived an expression for the moment of inertia of deformed nuclei. In statistical mechanics, he contributed many ideas to the understanding of ordering, including the concept of 'topological ordering'. Other important results relate to localised electron states in disordered lattices.
|
|
This isomerization mechanism shows prostaglandin H2 being converted to thromboxane. A heme group coordinated to a cysteine residue from the enzyme, thromboxane synthase, is involved in the mechanism. Thromboxane A (TXA) is derived from the prostaglandin H2 (PGH2) molecule. PGH2 contains a relatively weak epidioxy bond, and a possible mechanism is known to involve homolytic cleavage of the epidioxide and a rearrangement to TXA.
|
|
To introduce an MTM ether to a hydroxyl group, two methods are mainly used. One is a typical Williamson ether synthesis using an MTM halide as an MTM resource and sodium hydride (NaH) as a base. The other is a special method, in which dimethyl sulfoxide (DMSO) and acetic anhydride (Ac2O) are used. In this case, the reaction proceeds with Pummerer rearrangement: MTM ethers have another advantage.
|
|
The city was named after Jupiter Capitolinus. Evidence shows that the site was extensively settled and grew in importance during the Roman and Byzantine eras. Capitolias also had some importance in the early Islamic (Umayyad) period. In the rearrangement associated with the creation of the Roman province of Arabia in 106, Capitolias became part of the province of Palaestina Secunda, whose capital was Scythopolis.
|
|
"Embryonic and Postnatal Development of the Eye". Retrieved 22 April 2015. During the invagination of the optic cup, the ectoderm begins to thicken and form the lens placode, which eventually separates from the ectoderm to form the lens vesicle at the open end of the optic cup. Further differentiation and mechanical rearrangement of cells in and around the optic cup gives rise to the fully developed eye.
|
|
The Reading Company replaced Huntingdon Avenue station with North Broad Street station, a massive Classical Revival structure rivaling the PRR station in grandeur. 30th Street Station opened in 1933, reducing North Philadelphia's importance for north-south services. However, North Philadelphia continued to serve heavy commuter traffic and east-west long-distance trains. The lower level ticket counter in 1978 An interior rearrangement was completed around 1942.
|
|
NMDA receptors are "coincidence detectors". They determine when the presynaptic and postsynaptic neuron are linked in time via activity. When this occurs, NMDA receptors become the control mechanism that dictates how the AMPA and NMDA receptors are to be rearranged. The rearrangement of AMPA and NMDA receptors has become the central focus of current studies of metaplasticity as it directly determines LTP and LTD thresholds.
|
|
The background vocals are a particular feature of this album, with Quorthon multi-tracking himself, as he did on the Hammerheart album, though this time in a more sophisticated way, sounding like a whole chorus at times. The song entitled Hammerheart is based on a melody from Gustav Holst's The Planets. Specifically, it is Quorthon's own "rearrangement" of the middle section of the fourth movement, Jupiter.
|
|
Both the neutral and anionic variants of the oxy-Cope rearrangement may occur via either concerted or stepwise radical pathways, although the former mode is generally favored. The preferred intermediate is characterized by a chair-like conformation. Chirality transfer is effected by a highly ordered transition state. The positioning of the double bonds in the most readily accessible transition state determines the stereochemical course of the reaction.
|
|
Minor changes to the Turnbull Ministry took place following the resignation of Jamie Briggs and standing down of Mal Brough on 29 December 2015 and continued until 13 February 2016 when a rearrangement took place following the retirements of Andrew Robb (on 10 February 2016) and Warren Truss (on 11 February), and the resignations of Stuart Robert (on 12 February) and Brough (on 13 February).
|
|
When the Balkan Wars ended in autumn of 1913, the balance of power had changed. The Ottoman Empire had lost almost all its European holdings, Bulgaria was defeated, Serbia made some gains and Greece was enlarged. This rearrangement soon ignited a new crisis, the prelude to the First World War, which started on 28 July 1914. By September 1916, Bulgaria had seized considerable territories in northeastern Greece.
|
|
The range of the melody would have been "difficult to sing", so required rearrangement. A jazz/traditional pop arrangement was recorded by Louis Armstrong (vocals) and arranger Gordon Jenkins, with "some of Armstrong's most honey-tinged singing". Jenkins would in 1956 produce a version with Nat King Cole along the same lines. In 1958, Edwards had only one session left on his MGM contract.
|
|
In this rearrangement of Liliaceae, with fewer subdivisions, the core Liliales were represented as subfamily Lilioideae (with Tulipae and Scilleae as tribes), the Asparagae were represented as Asparagoideae and the Allioideae was preserved, representing the alliaceous genera. Allieae, Agapantheae and Gilliesieae were the three tribes within this subfamily. In the Amaryllidacea, there was little change from the Bentham & Hooker. A similar approach was adopted by Wettstein.
|
|
4-Aminopyridine is prepared by the decarbonylation of pyridine-4-carboxamide using sodium hypochlorite via the Hofmann rearrangement. The pyridine carboxamide is generated from the corresponding nitrile, which in turn is obtained from ammoxidation of 4-methylpyridine.Shinkichi Shimizu, Nanao Watanabe, Toshiaki Kataoka, Takayuki Shoji, Nobuyuki Abe, Sinji Morishita, Hisao Ichimura "Pyridine and Pyridine Derivatives" in "Ullmann's Encyclopedia of Industrial Chemistry" 2007; John Wiley & Sons: New York.
|
|
As with any material, the existence of a crystallographic defect affects the material properties. Defects can occur in the form of atomic vacancies. High levels of such defects can lower the tensile strength by up to 85%. An important example is the Stone Wales defect, otherwise known as the 5-7-7-5 defect because it creates a pentagon and heptagon pair by rearrangement of the bonds.
|
|
This linkage map may identify distances from other genes using (cM) centiMorgans as a unit of measurement. Co-dominant markers can be used in mapping, to identify particular locations within a genome and can represent differences in phenotype. Linkage of markers can help identify particular polymorphisms within the genome. These polymorphisms indicate slight changes within the genome that may present nucleotide substitutions or rearrangement of sequence.
|
|
It is the simplest point defect. In this system, an atom is missing from its regular atomic site. Vacancies are formed during solidification due to vibration of atoms, local rearrangement of atoms, plastic deformation and ionic bombardments. The creation of a vacancy can be simply modeled by considering the energy required to break the bonds between an atom inside the crystal and its nearest neighbor atoms.
|
|
In all, when she surveyed the entire extant corpus of Trotula manuscripts in 1996, Green identified eight different versions of the Latin Trotula ensemble. These versions differ sometimes in wording, but more obviously by the addition, deletion, or rearrangement of certain material. The so-called "standardized ensemble" reflects the most mature stage of the text, and it seemed especially attractive in university settings.Green, The 'Trotula, p. 58.
|
|
The mechanism in which external factors stimulate growth and rearrangement is not yet fully understood. A number of growth factors and neurohumoral agents influence smooth muscle growth and differentiation. The Notch receptor and cell-signaling pathway have been demonstrated to be essential to vasculogenesis and the formation of arteries and veins. The proliferation is implicated in the pathogenesis of atherosclerosis and is inhibited by nitric oxide.
|
|
Carbocation rearrangement reactions occur through three-center bond transition states. Because the three center bond structures have about the same energy as carbocations, there is generally virtually no activation energy for these rearrangements so they occur with extraordinarily high rates. Carbonium ions such as ethanium have three-center two-electron bonds. Perhaps the best known and studied structure of this sort is the 2-Norbornyl cation.
|
|
Collagen is synthesized as a soluble precursor, procollagen, which supports collagen self-assembly. Since collagen fibrils have almost 50 binding components in vivo, the definite requirement to generate fibrillogenesis in vivo is still cryptic. With acidic or saline solution, collagen can be extracted from tissues and rearrange into fibril by changing temperature or pH value. Experiments discovered attractive force between collagen monomers which helps the rearrangement.
|
|
Sphingonotus caerulans is a species belonging to the family Acrididae subfamily Oedipodinae.The northern limit is northern France, eastern Sweden and southern Finland. In Central and Northern Europe the species is restricted to low-vegetation special habitats, in which the soil remains free of vegetation through constant rearrangement (pioneer species of open habitats).it is very common especially in rocky heaths in the Mediterranean area.
|
|
"Die Prophezeiung review on Sa-CD.net". Retrieved 10 September 2016. A special edition of Die Prophezeiung, with a classical rearrangement, was released under the title Die Prophezeiung: Klassik Edition."Die Prophezeiung: Klassik Edition on Last.FM". Retrieved 10 September 2016. In 2004, the project released their final work together, a compilation entitled Das Beste aus... Gottes Beitrag und Teufels Werk, which also presented new songs.
|
|
Ramberg–Bäcklund synthesis of allyl alcohols The Favorskii rearrangement and the Eschenmoser sulfide contraction are conceptually related reactions. A recently developed application of the Ramberg–Bäcklund reaction is the synthesis of C-glycosides. The required thioethers can be prepared easily by exchange with a thiol. The application of the Ramberg–Bäcklund conditions then leads to an exocyclic vinyl ether that can be reduced to the C-nucleoside .
|
|
Many physical changes also involve the rearrangement of atoms most noticeably in the formation of crystals. Many chemical changes are irreversible, and many physical changes are reversible, but reversibility is not a certain criterion for classification. Although chemical changes may be recognized by an indication such as odor, color change, or production of a gas, every one of these indicators can result from physical change.
|
|
The reactive oxygen species are capable of stressing the endoplasmic reticulum, which increases the amount of the unfolded protein response signals. This leads to inflammation, cell proliferation, and eventually to cell death. Another mechanism in which reactive oxygen species cause cell death would be through the cytoskeleton rearrangement, which affects the contractile proteins. The reactive nitrogen species arise once the reactive oxygen species destroy the mitochondria.
|
|
Another isotype, shark IgW, is related to mammalian IgD. TCRs, both α/β and γ/δ, are found in all animals from gnathostomes to mammals. The organization of gene segments that undergo gene rearrangement differs in cartilaginous fishes, which have a cluster form as compared to the translocon form in bony fish to mammals. Like TCR and Ig, the MHC is found only in jawed vertebrates.
|
|
Though the molecules of the AIS are well-conserved, they are also rapidly evolving. Yet, a comparative approach finds that many features are quite uniform across taxa. All the major features of the AIS arose early and quickly. Jawless fishes have a different AIS that relies on gene rearrangement to generate diverse immune receptors with a functional dichotomy that parallels Ig and TCR molecules.
|
|
In November 2017 a complete rearrangement of the plateau, which functioned as an extension of the Tašmajdan Park in front of the church, began. Old asphalt pavement which served as a parking lot was removed. Architect Jovan Mitrović designed a new, leveled combination of granite slabs and green areas. The plateau will be divided in two sections, left and right, divided by the green island.
|
|
This gene encodes a tumor suppressor protein that can induce cell growth arrest and apoptosis. The encoded protein is a nuclear protein that physically interacts with the tumor suppressor protein TP53 and is a component of the p53 signaling pathway. Reduced expression and rearrangement of this gene have been detected in various cancers. Multiple alternatively spliced transcript variants encoding distinct isoforms have been reported.
|
|
In 1982, the Guggenheim Foundation premiere of Kandinsky's opera Der gelbe Klang was made possible thanks to a complete rearrangement by Gunther Schuller of De Hartmann's hitherto lost work. It is not known whether De Hartmann completed a full score but it is clear why Konstantin Stanislavski could not understand the work when de Hartmann proposed it for the Moscow Art Theatre in 1914.
|
|
It facilitates DNA repair by recombination. 4\. Recently many novel functions of cohesin have been discovered in many different cellular processes. Cohesin has been shown to be responsible for transcription regulation, DNA double strand break repair, chromosome condensation, pairing of homologous chromosomes during meiosis I, mono-orientation of sister kinetochores during meiosis I, non-homologous centromere coupling, chromosome architecture and rearrangement, DNA replication etc.
|
|
Schematic flow diagram of a fluid catalytic cracker The catalytic cracking process involves the presence of solid acid catalysts, usually silica-alumina and zeolites. The catalysts promote the formation of carbocations, which undergo processes of rearrangement and scission of C-C bonds. Relative to thermal cracking, cat cracking proceeds at milder temperatures, which saves energy. Furthermore, by operating at lower temperatures, the yield of alkenes is diminished.
|
|
Isomaltulose, also known by the trade name Palatinose, is manufactured by enzymatic rearrangement (isomerization) of sucrose from beet sugar. The enzyme and its source were discovered in Germany in 1950, and since then its physiological role and physical properties have been studied extensively.Sentko, A. and Willibald-Ettle, I. (2012). "Isomaltulose." In: Sweeteners and Sugar Alternatives in Food Technology, 2nd Ed. Editors O'Donnell, K. & Kearsley, M.W. Wiley-Blackwell.
|
|
Regeneration in hydra has been defined as morphallaxis, the process where regeneration results from remodeling of existing material without cellular proliferation. If a hydra is cut into two pieces, the remaining severed sections form two fully functional and independent hydra, approximately the same size as the two smaller severed sections. This occurs through the exchange and rearrangement of soft tissues without the formation of new material.
|
|
People with Emanuel syndrome typically inherit the der(22) chromosome from an unaffected parent. The parent carries a chromosomal rearrangement between chromosomes 11 and 22 called a balanced translocation. No genetic material is gained or lost in a balanced translocation, so these chromosomal changes usually do not cause any health problems. As this translocation is passed to the next generation, it can become unbalanced.
|
|
T1 process: four objects swap neighbours. Such a process is common during liquid foam or biological tissue deformation. A T1 process (or topological rearrangement process of the first kind)D. Weaire, S. Hutzler, "The Physics of Foams", Oxford University Press, 1999, , I. Cantat, S. Cohen-Addad, F. Elias, F. Graner, R. Höhler, O. Pitois, F. Rouyer, A. Saint-Jalmes, "Foams: structure and dynamics", Oxford University Press, ed.
|
|
Thomas then goes to the Bathysphere and a very confusing scene occurs. Thomas opens a pale gold door and suddenly he has a flashback of his entire life. After these flashbacks, his view of the Divided Kingdom has changed. The guests attending the conference at the Blue Quarter are moved into the Yellow Quarter for reasons that are not quite clear, possibly because it is Rearrangement Day.
|
|
All of the Pieces is the first extended play (EP) by Derry, released through Sony Music Australia on 12 December 2014. The five-track EP contains her debut solo single of the same name and four studio recordings of songs she performed as a top twelve finalist on The X Factor Australia, including a previously unheard downtempo rearrangement of Rihanna's "Only Girl (In the World)".
|
|
The subwall will also be renovated and the ruined stone slabs will be replaced. Second phase, which includes the rearrangement of the wider surrounding area of the Big Staircase is set for October 2020. However, when works began in March 2019, instead of restoration and repair of the staircase, it was actually smashed. Architects and art historians protested, but city administration said "this is the best way".
|
|
Free carbenes can be employed for cyclopropanation reactions, however there is limited scope for this as few can be produced conveniently and nearly all are unstable (see: carbene dimerization). An exception are dihalocarbenes such as dichlorocarbene or difluorocarbene, which are reasonably stable and will react to form geminal dihalo-cyclopropanes. These compounds can then be used to form allenes via the Skattebøl rearrangement. :File:Dichlorocarbene reaction cyclohexene.
|
|
ATCs were first used on chip-removal machinery, such as mills and lathes. Systems for automatic rearrangement of tools have also been used on sheet metal working machinery as well. Panel benders have an integrated, CNC-controlled device that allows to move punches according to the size of the part. Automated tool change on press brakes was limited to machines integrated on a robotic bending cell.
|
|
This latter cumene converts into cumene radical and feeds back into subsequent chain formations of cumene hydroperoxides. A pressure of 5 atm is used to ensure that the unstable peroxide is kept in liquid state. ::300px ::450px Cumene hydroperoxide is then hydrolysed in an acidic medium (the Hock rearrangement) to give phenol and acetone. In the first step, the terminal hydroperoxy oxygen atom is protonated.
|
|
The other electron from the bond moves to an adjacent atom (not one adjacent to the lone pair atom) creating a radical. This creates a double bond adjacent to the lone pair atom (oxygen is a good example) and breaks/cleaves the bond from which the two electrons were removed. :Example of alpha cleavage In molecules containing carbonyl groups, alpha-cleavage often competes with McLafferty rearrangement.
|
|
In some cancers the genes that underlie the defects resulting in transformation are well characterized. In the hematological cancers such as multiple myeloma cytogenetic abnormalities are very common due to the inherent nature of DNA breaks needed for immunoglobulin gene rearrangement. However, defects in proteins such as MAD2 that function predominantly at the SAC also are characterized in multiple myeloma. Most solid tumors are also predominantly aneuploid.
|
|
In 1845, he was appointed inspector of Welsh roads and assisted the county authorities in the rearrangement of the public roads as a consequence of the abolition of turnpikes. In 1846, he was appointed joint secretary with the Hon. F. Bruce to the new railway commission. When this commission was merged in a department of the board of trade, Harness remained as sole secretary.
|
|
This observed cis diastereoselectivity is due to the intermediate formation of a trichlorotitanium alkoxide making possible an easy delivery of chlorine to the carbocation ion from the same face. The trans isomer is preferred (98% cis) when the switch is made to a tin tetrachloride reaction at room temperature. Scheme 7. Halo-Prins reaction The Prins-pinacol reaction is a cascade reaction of a Prins reaction and a pinacol rearrangement.
|
|
Before the opening credits, the words "This show is for SAM" appear. This is a reference to comedian Sam Kinison, who had died in a car crash two weeks before the recording. Carlin considered Jammin' in New York his favorite and best HBO special. This is also the first Carlin album to more-or-less contain the entire audio of his HBO special without interruption, deletion, or rearrangement.
|
|
Moorella is a genus of bacteria belonging to the phylum Firmicutes. These bacteria are thermophilic, anaerobic and endospore-forming and many species of this genus have been isolated from hot springs. Some of these species were formerly included within the genus Clostridium, but after a taxonomic rearrangement of the class Clostridia, a phylogenetically distinct genus was identified, which was named Moorella in honor of the American microbiologist W.E.C. Moore.
|
|
Two of the ousted MPs – Joyce and Nash – were members of Cabinet, requiring a rearrangement of the Second Turnbull Ministry, which took place on the same day. Canavan, who had stepped down from Cabinet pending the court's decision, was returned to Cabinet. Replacements of three of the four disqualified Senators were announced on 10 November. Ludlam was replaced by Jordan Steele-John; Waters by Andrew Bartlett and Roberts by Fraser Anning.
|
|
The frequency at which S. castellii spontaneously produces petites is similar to that of S. cerevisiae, with the mitochondrial DNA of those petites being highly altered via deletion and rearrangement. Suppressive petites of S. cerevisiae are the most commonly observed spontaneously created mutants, whereas in S. castellii, the most commonly observed spontaneous mutant is the neutral petite, further leading to speculation that the transference of this mutation differs between species.
|
|
The instrument was modified repeatedly by the firm over time. In 1913, a substantial renovation took place in the course of which the organ received tubular-pneumatic action, cone chests, a free-standing console, an expression pedal and several new registers. A further rearrangement followed in 1941 in the course of the organ reform movement. In 1961, the empty rear housing was refilled with new registers in a slider chest.
|
|
Caprolactam is the feedstock in the production of Nylon 6. The Beckmann solution consists of acetic acid, hydrochloric acid and acetic anhydride, and was widely used to catalyze the rearrangement. Other acids, such as sulfuric acid, polyphosphoric acid, and hydrogen fluoride have all been used. Sulfuric acid is the most commonly used acid for commercial lactam production due to its formation of an ammonium sulfate by-product when neutralized with ammonia.
|
|
Another difference is that the barrelene reaction requires the triplet excited state while the Mariano and Pratt acyclic dienes used the excited singlet. Thus acetone is used in the barrelene reaction; acetone captures the light and then delivers triplet excitation to the barrelene reactant. In the final step of the rearrangement there is a spin- flip, termed intersystem-crossing (ISC) to provide paired electrons and a new sigma bond. Equation 3.
|
|
Zinc metal is inserted into the carbon-halogen bond of the α-haloester by oxidative addition 1. This compound dimerizes and rearranges to form two zinc enolates 2. The oxygen on an aldehyde or ketone coordinates to the zinc to form the six-member chair like transition state 3. A rearrangement occurs in which zinc switches to the aldehyde or ketone oxygen and a carbon-carbon bond is formed 4.
|
|
Darren Jeffrey Chester (born 13 September 1967) is an Australian politician. He has been a member of the House of Representatives for Gippsland in Victoria, representing the Nationals since 2008. Chester has served as the Minister for Veterans' Affairs and the Minister for Defence Personnel since , following a rearrangement of the second Turnbull Ministry. He was also Minister Assisting the Prime Minister for the Centenary of ANZAC until May 2019.
|
|
The species was named to honour the German ornithologist Hans von Berlepsch. The species was later placed in the genus Myrmeciza but a molecular phylogenetic study published in 2013 found that the genus Myrmeciza, as then defined, was polyphyletic. In the resulting rearrangement to create monophyletic genera the stub-tailed antbird was moved to a resurrected genus Sipia which had been introduced by the Austrian ornithologist Carl Eduard Hellmayr in 1924.
|
|
Best Battleship: Underwater Protection (CombinedFleet.com) By adopting a turbo-electric drive, this allowed a wholesale rearrangement and close subdivision of the machinery spaces, while simultaneously narrowing them and permitting more space outboard for a layered system of voids, liquid-filled tanks and thin armored bulkheads.A Survey of the American "Standard Type" Battleship (navweaps.com) By contrast, "thin-skinned" cruisers and carriers relied only on numerous compartments to prevent flooding from spreading.
|
|
Hot pressing is mainly used to fabricate hard and brittle materials. One large use is in the consolidation of diamond-metal composite cutting tools and technical ceramics. The densification works through particle rearrangement and plastic flow at the particle contacts. The loose powder or the pre-compacted part is in most of the cases filled to a graphite mould that allows induction or resistance heating up to temperatures of typically .
|
|
Human lymphatic endothelial cells (LECs) abundantly express GPR97. Silencing GPR97 in human LECs indicated that GPR97 modulates cytoskeletal rearrangement, cell adhesion and migration through regulating the small GTPase RhoA and cdc42. In vertebrates, GPR97 has an indispensable role in the bone morphogenetic proteins (BMP) signaling pathway in bone formation. A microarray meta-analysis revealed that mouse Gpr97 is a direct transcriptional target of BMP signaling in long bone development.
|
|
Under his supervision in 1970, doctoral student Denis Lauren first isolated the diterpene compound from the rimu tree (Dacrydium cupressinum) that came to be known as laurenene. Corbett also investigated extractives from barks, leaves, heartwoods and lichens, and determined the structures of many new, and derivatives of known, di-, tri- and sesquiterpenoids. He also studied the synthesis and rearrangement of some of the compounds that his team isolated.
|
|
In chemistry isomerization or isomerisation is the process in which a molecule, ion or molecular fragment is transformed into an isomer with a different chemical structure. Enolization is an example of isomerization, as is tautomerization. When the isomerization occurs intramolecularly it may be called a rearrangement reaction. When the activation energy for the isomerization reaction is sufficiently small, both isomers will exist in a temperature-dependent equilibrium with each other.
|
|
Both cases were caused by a rearrangement of national boundaries. However, families can also be divided if national boundaries remain unchanged, but instead groups of people or invidviduals are moved, forced to leave or flee. Forced displacement such as flight from persecution, violence or a severe lack of public order can be causes of divided families. For example, over 100,000 unaccompanied minors applied for asylum in other countries in 2015.
|
|
The rearrangement proof (click to view animation)The two large squares shown in the figure each contain four identical triangles, and the only difference between the two large squares is that the triangles are arranged differently. Therefore, the white space within each of the two large squares must have equal area. Equating the area of the white space yields the Pythagorean theorem, Q.E.D.Benson, Donald. The Moment of Proof : Mathematical Epiphanies, pp.
|
|
Iridium tetroxide (IrO4, Iridium(VIII) oxide) is a binary compound of oxygen and iridium in oxidation state +8. This compound was formed by photochemical rearrangement of (η1-O2)IrO2 in solid argon at a temperature of . At higher temperatures, the oxide is unstable. The detection of the iridium tetroxide cation by infrared photodissociation spectroscopy with formal oxidation state +9 has been reported, the highest currently known of any element.
|
|
L-phenylalanine is first hydroxylated by CYP79D16, followed by a decarboxylation and dehydration, forming the E-oxime phenylacetaldoxime. Next, CYP71AN24 catalyzes the rearrangement of the E-oxime to the Z-oxime followed by a dehydration and a hydroxylation to form mandelonitrile. Finally, UGT85A19 or UGT94AF3 utilize UDP-glucose to glycosylate mandelonitrile, forming (R)-prunasin. After generating (R)-prunasin, the product is further glycosylated into amydgalin by either isoform UGT94AF1 or UGT94AF2.
|
|
When receptors come in contact with cell surface markers on the apoptotic cell, a protein known as CED-6 (homolog for GULP in mammals) is expressed. Both the CED-2/CED-5/CED-12 ternary structure and CED-6 function to activate an effector protein known as CED-10. CED-10 is a RAC-GTPase protein that is directly responsible for the rearrangement of the actin cytoskeleton that initiates phagocytosis.
|
|
They inferred a phylogeny very greatly different from George's taxonomic arrangement, including finding Banksia to be paraphyletic with respect to Dryandra. A new taxonomic arrangement was not published at the time, but early in 2007 Mast and Thiele initiated a rearrangement by transferring Dryandra to Banksia, and publishing B. subg. Spathulatae for the species having spoon-shaped cotyledons. They foreshadowed publishing a full arrangement once DNA sampling of Dryandra was complete.
|
|
Fusion of an alicyclic ring onto the piperidine so as to form a perhydroisoquinoline is apparently consistent with analgesic activity. Ciprefadol synthesis: D. M. Zimmerman and VI. S. Marshall, Eli Lilly; (1977). Synthesis of this agent, ciprefadol (12), starts with the Michael addition of the anion from cyclohexanone (1) onto acrylonitrile. Saponification of the nitrile (2) to the corresponding acid (3) followed by Curtius rearrangement leads to isocyanate (5).
|
|
Some cases of reactions that were not really discovered by their namesakes are known. Examples include the Pummerer rearrangement, the Pinnick oxidation and the Birch reduction. Although systematic approaches for naming reactions based on the reaction mechanism or the overall transformation exist (such as the IUPAC Nomenclature for Transformations), the more descriptive names are often unwieldy or not specific enough, so people names are often more practical for efficient communication.
|
|
He was voluntarily removed from cabinet in the December 2017 rearrangement. On 24 August 2018, Sinodinos returned to Canberra and attended the Liberal Party meeting where Malcolm Turnbull was replaced by Scott Morrison as Leader.Dutton hands spill petition to Prime Minister Malcolm Turnbull, ABC News Online, 2018-08-24 In TV coverage, he could be seen being greeted by Whip, Nola Marino, and various others after the meeting.
|
|
FN3K catalyzes phosphorylation of fructosamines formed by glycation, the nonenzymatic reaction of glucose with primary amines followed by Amadori rearrangement. Phosphorylation of fructosamines may initiate metabolism of the modified amine and result in deglycation of glycated proteins. FN3K is responsible for the formation of fructose 3-phosphate (F3P), a compound identified in the lenses of diabetic rats. The spontaneous decomposition of F3P leads to the formation of 3-deoxyglucosone (3DG).
|
|
The Tishchenko reaction produces esters from an aldehyde and a ketone, or two equivalents of an aldehyde, in the presence of a metal alkoxide catalyst. Also named after him is the 'Tishchenko flask', a type of glassware used in absorption of gases. In 1931, Tishchenko undertook work on the synthesis of camphene from pinene via a Wagner–Meerwein rearrangement. Similar methods were later used by Shering Company in the industrial synthesis.
|
|
At the time, the roof was supported by sixteen granite columns. In 1981, the Benedictine Monastery decided that they wanted a space that reflected their new awareness of modern Benedictine spirituality. The chapel was extensively renovated, which involved rearrangement of the seating and the removal of eight of the granite columns. The columns that were removed were incorporated into the Gathering Place, an addition to the west side of the chapel.
|
|
Disruption of TAD boundaries can affect the expression of nearby genes, and this can cause disease. For example, genomic structural variants that disrupt TAD boundaries have been reported to cause developmental disorders such as human limb malformations. Additionally, several studies have provided evidence that the disruption or rearrangement of TAD boundaries can provide growth advantages to certain cancers, such as T-cell acute lymphoblastic leukemia (T-ALL), gliomas, and lung cancer.
|
|
An isomerization reaction then occurs, followed by a hydroxylation and rearrangement of the phenol group to form 2,4',7-trihydroxyisoflavonone. This molecule can then follow one of two paths, both of which include the loss of water and a methylation to produce formononetin. This product then undergoes hydroxylation to form calycosin, followed by the formation of a dioxolane ring. Another hydroxylation then occurs, followed by an isomerization to form (-)sopherol.
|
|
In both cases, the inverted duplicated marker forms only after cell division and replication by rejoining the broken, replicated ends of the fragment. It is also suggested that U-type exchange during meiosis I may lead to partial tetrasomy. On the other hand, Class II marker chromosomes result from the second most common type of rearrangement: interstitial deletions. A chromosome is rearranged to give a ring chromosome, and a linear chromosome.
|
|
Thrombospondin-1 (TSP-1) is a matricellular glycoprotein found in plasma of healthy patients with levels in the range of 50–250 ng/ml. TSP-1 levels are known to increase in response to injury and during development. TSP-1 activates latent TGF-beta by forming direct interactions with the latent TGF-β complex and induces a conformational rearrangement preventing it from binding to the matured TGF-β.
|
|
The majority of chronic myelogenous leukemia cases are caused by a rearrangement between chromosomes 9 and 22. This results in the fusion of the genes BCR and ABL. This atypical gene fusion encodes for unregulated tyrosine kinase activity, which results in the rapid and continuous division of white blood cells. Drugs known as tyrosine kinase inhibitors target BCR-ABL, and are the standard treatment for chronic myelogenous leukemia.
|
|
Molecular phylogenetic studies in the 21st century have resulted in substantial rearrangement of the species in this tribe, many being moved to different genera. S. leimanthoides was previously placed in Zigadenus as Z. leimanthoides, and will be found under this name in older sources. It is native to the southernmost United States, more inland than S. densum, largely in the Appalachian Mountains. The plants endanger livestock, particularly in the West.
|
|
1,3-dipolar cycloaddition reactions have emerged as powerful tools in the synthesis of complex cyclic scaffolds and molecules for medicinal, biological, and mechanistic studies. Among them, [3+2] cycloaddition reactions involving carbonyl ylides have extensively been employed to generate oxygen-containing five-membered cyclic molecules.Synthetic Reactions of M=C and M=N Bonds: Ylide Formation, Rearrangement, and 1,3-Dipolar Cycloaddition; Hiyama, T. W., J., Ed.; Elsevier, 2007; Vol. 11.
|
|
However, this is only possible for a relatively small number of sequences or species because the problem of identifying the most parsimonious tree is known to be NP-hard; consequently a number of heuristic search methods for optimization have been developed to locate a highly parsimonious tree, if not the best in the set. Most such methods involve a steepest descent-style minimization mechanism operating on a tree rearrangement criterion.
|
|
In less than 20%, inheritance is through an autosomal dominant pattern. The parent is usually unaffected, but carries a particular chromosomal rearrangement called a balanced translocation, in which no genetic material is gained or lost. Increased rate of unexplained fetal loss may be observed in MDS carriers with balanced translocations although they may be otherwise asymptomatic. However, they can become also unbalanced as they are passed to the next generation.
|
|
The complete phrase which was used by the Nazi establishment was actually die Neuordnung Europas (the New Order of Europe), for which Neuordnung was merely a shorthand. According to the Nazi government this goal was pursued by Germany to secure a fair rearrangement of territory for the common benefit of a new, economically integrated Europe,Spielvogel, Jackson J. (2006). Western Civilization Since 1789, Volume 3. Clark Baxter, p. 855.
|
|
A variety of allylic ethers undergo the Wittig rearrangement—the fundamental requirement is the ability to generate the appropriate carbanion in the substrate. This demands either acidic hydrogens, a reducible functional group, or a carbon-metal bond. Historically, alkenyl, alkynyl, and phenyl groups have been used to acidify the α position. Free terminal alkynes are tolerated, although yields are higher when silyl-protected alkynes are used. (7)File:23Scope3.
|
|
The Impossible Man's alien physiology gives the character the ability to take on virtually any form via molecular rearrangement, an effect commonly accompanied by a "Pop!" sound effect. He can mirror the properties of objects or super-powered beings he shapeshifts into. Almost every appearance has featured the Impossible Man mimicking another Marvel character's appearance and their abilities, such as Thor, Klaw,Fantastic Four #187 (Oct. 1976) and Wolverine.
|
|
In 1992, a RAG2 knockout mice strain was generated. Since then, it became a widely used mouse model in immunological research. This mice strain has an inactivated RAG2 gene, therefore homozygous mice are inable to initiate V(D)J rearrangement and consequently fail to generate mature T and B lymphocytes. As such RAG2 knockout mice represent a very valuable research tool used in transplantation experiments, vaccine development and hematopoiesis research.
|
|
Since the federal rearrangement of the Ethiopian state in the 1990s, "the Dubamo increasingly became aware of their non-Hadiya origin and started demanding an administrative district of their own".Braukämper, U. "Controversy over local tradition and national Ethiopian Context: Case study of the Hadiyya", in: Afrikas Horn: Akten der Ersten Internationalen Littmann- Konferenz, 2. bis 5. Mai 2002 in München (Wiesbaden: Harrassowitz Verlag, 2005), pp. 363-376.
|
|
The nomes survived into Roman times. Under Roman rule, individual nomes minted their own coinage, the so-called "nome coins," which still reflect individual local associations and traditions. The nomes of Egypt retained their primary importance as administrative units until the fundamental rearrangement of the bureaucracy during the reigns of Diocletian and Constantine the Great. From AD 307/8, their place was taken by smaller units called pagi.
|
|
The Methodist church, built in 1812 at Gorehedge, is still in use after considerable additions in 1863, restoration in 1871 and major internal rearrangement in the 1980s. Sun Street Chapel was erected by the Primitive Methodists in 1834, and closed in 1982, although it was used by another religious group afterwards. It is now used as a Community Centre. There is another Methodist church on Portway, built in 1910.
|
|
A base abstracts the hydrogen atom alpha to the aromatic ketone, forming an enolate. Then, the enolate attacks the ester carbonyl to form a cyclic alkoxide. The cyclic intermediate is opened up to form a more stable phenolate, which is protonated during acidic work-up to give the desired product. The Baker-Venkataraman rearrangement mechanism To complete the construction of the chromone or flavone core, cyclodehydration is required.
|
|
Carbon-localized free radicals and cations are both highly unstable and undergo processes of chain rearrangement, C–C scission in position beta (i.e., cracking) and intra- and intermolecular hydrogen transfer or hydride transfer. In both types of processes, the corresponding reactive intermediates (radicals, ions) are permanently regenerated, and thus they proceed by a self- propagating chain mechanism. The chain of reactions is eventually terminated by radical or ion recombination.
|
|
Black's Equation is a mathematical model for the mean time to failure (MTTF) of a semiconductor circuit due to electromigration: a phenomenon of molecular rearrangement (movement) in the solid phase caused by an electromagnetic field. The equation is: R. L. de Orio. Dissertation: "Electromigration Modeling and Simulation". 2010\. R.L. de Orio, H. Ceric, S. Selberherr. "Physically based models of electromigration: From Black’s equation to modern TCAD models" Microelectronics Reliability journal. 2010\.
|
|
Lande, R. (1979) Effective Deme Sizes During Long-Term Evolution Estimated from Rates of Chromosomal Rearrangement. Evolution 33:234–251 Lande reconciled Wright's population-level view with Simpson's use of higher taxonomic levels. Lande considers fitness peaks to be determined by the environment and thus represent ecological niches or adaptive zones for a population. Clusters of peaks inhabited by phenotypically similar populations can be viewed as higher taxonomic levels.
|
|
The cationic rearrangement contraction proceeds through the loss of a leaving group and the migration of an endocyclic bond to the carbocation. Pinacol type rearrangements are often used for this type of contraction. Like the expansion reaction this proceeds with an electron donating group aiding in the migration. Contraction reactions of one ring can be coupled with an expansion of another to give an unequal bicycle from equally sized fused ring.
|
|
Particularly hostile were followers of Robert Muldoon, a traditionalist conservative who opposed free market reforms as undermining state authority. Shortly after National's electoral loss, Jim McLay replaced Muldoon as leader of the National Party and he appointed Richardson education spokesperson. In February 1986 there was a considerable rearrangement of responsibilities in the opposition. People such as Bill Birch and George Gair, who McLay associated with the Muldoon era, were demoted.
|
|
This reaction, saponification, is the basis of soap making. :Ester saponification (basic hydrolysis) The alkoxide group may also be displaced by stronger nucleophiles such as ammonia or primary or secondary amines to give amides: (ammonolysis reaction) :: RCO2R′ + NH2R″ → RCONHR″ + R′OH This reaction is not usually reversible. Hydrazines and hydroxylamine can be used in place of amines. Esters can be converted to isocyanates through intermediate hydroxamic acids in the Lossen rearrangement.
|
|
Most recently, Caldwell and Cordiner collaborated with Hill on a paper entitled "Phosphino and phosphonito carbyne complexes" "Phosphino and phosphonito carbyne complexes: [Mo(≡CX)(CO)2{HB(pzMe2)3}] (X = PPh2, P(=O)(OEt)2; pz = pyrazol-1-yl)" Caldwell L.M., Cordiner R.L., Hill A.F., Wagler J. "A bridging selenoacyl complex via alkynylselenolatoalkylidyne rearrangement". Organometallics (2010), 29(7), 1526 - 1529. Hill is author of a textbook entitled Organotransition Metal Chemistry.
|
|
However, their allies rejected the rearrangement and went home.Thucydides, 5.54. Aristophanes' Clouds, a comedy from 423 BC, contains a speech whose complaint is brought from the moon: the Athenians have been playing round with the months, "running them up and down" so that human activity and the divine order are completely out of kilter: "When you should be holding sacrifices, instead you are torturing and judging."Aristophanes. Clouds, 615-626.
|
|
A mass spectrum can represent many different types of information based on the type of mass spectrometer and the specific experiment applied; however, all plots of intensity vs. mass-to-charge are referred to as mass spectra. Common fragmentation processes for organic molecules are the McLafferty rearrangement and alpha cleavage. Straight chain alkanes and alkyl groups produce a typical series of peaks: 29 (CH3CH2+), 43 (CH3CH2CH2+), 57 (CH3CH2CH2CH2+), 71 (CH3CH2CH2CH2CH2+) etc.
|
|
Two common side reactions are elimination reactions and carbocation rearrangement. If the reaction is performed under warm or hot conditions (which favor an increase in entropy), E1 elimination is likely to predominate, leading to formation of an alkene. At lower temperatures, SN1 and E1 reactions are competitive reactions and it becomes difficult to favor one over the other. Even if the reaction is performed cold, some alkene may be formed.
|
|
"Gergeza" was preferred over "Geraza" or "Gadara" (Commentary on John VI.40 (24) - see ). Most of the variations are not significant and some common alterations include the deletion, rearrangement, repetition, or replacement of one or more words when the copyist's eye returns to a similar word in the wrong location of the original text. If their eye skips to an earlier word, they may create a repetition (error of dittography).
|
|
The above mechanism is consistent with all available experimental evidence. The equilibrium between species 1 and 2 is supported by 18O Isotopic labeling experiments. In deuterated water, carbonyl oxygen exchange occurs much faster than the rearrangement, indicating that the first equilibrium is not the rate-determining step. Further experiments showed a larger relative rate in a deuterated solvent system compared to a non- deuterated solvent system of otherwise identical composition.
|
|
This gene encodes a protein that belongs to the non-histone chromosomal high-mobility group (HMG) protein family. HMG proteins function as architectural factors and are essential components of the enhanceosome. This protein contains structural DNA-binding domains and may act as a transcriptional regulating factor. Identification of the deletion, amplification, and rearrangement of this gene that are associated with lipomas suggests a role in adipogenesis and mesenchymal differentiation.
|
|
The 2009 ATP World Tour Finals (also known as the 2009 Barclays ATP World Tour Finals for sponsorship reasons) was held in London, United Kingdom between 22 November and 29 November 2009. It was the first time the O2 arena hosted the ATP World Tour Year-End Singles and Doubles Championships. The event was renamed from Tennis Masters Cup to ATP World Tour Finals following the rearrangement of the ATP Tour.
|
|
Brigatinib is an inhibitor of ALK and mutated EGFR. ALK was first identified as a chromosomal rearrangement in anaplastic large cell lymphoma (ALCL). Genetic studies indicate that abnormal expression of ALK is a key driver of certain types of non-small cell lung cancer (NSCLC) and neuroblastomas, as well as ALCL. Since ALK is generally not expressed in normal adult tissues, it represents a highly promising molecular target for cancer therapy.
|
|
A characteristic of many cancer cells is that parts of some genes contained within these cells have been recombined with other genes. One such gene fusion that has been identified in a MCF-7 breast cancer cell line is a chimera between the RAD51C and ATXN7 genes. Since the RAD51C protein is involved in repairing double strand chromosome breaks, this chromosomal rearrangement could be responsible for the other rearrangements.
|
|
The role of these substrates has not yet been defined. Both though, along with their interactions, are removed in the maturation process of the 60S pre-ribosome. The other two ATPases, Rix7 and Drg1 also function to remove assembly factors from the maturing 60S subunit. Helicases and GTPases are also involved in the removal of assembly factors and the rearrangement of RNA to form the completed 60S subunit.
|
|
In effect, the whole map is a square, inspiring Peirce to call his projection quincuncial, after the arrangement of five items in a quincunx. After Peirce presented his projection, two other cartographers developed similar projections of the hemisphere (or the whole sphere, after a suitable rearrangement) on a square: Guyou in 1887 and Adams in 1925. The three projections are transversal versions of each other (see related projections below).
|
|
Shikata continues to work with the Ar tonelico franchise today, releasing music for both the second and third games. Her second major-label album, Raka, was released in 2006. It featured several songs from games (two songs used in Hanakisō, as well as a rearrangement of the opening theme song from Ar tonelico, ). It was her first top 40 album, ranking at #34 on the Oricon albums chart.
|
|
It is prepared industrially by two routes. Annual production in 1993 was estimated to be 4M kg. The main method involves the thermal rearrangement of methyl thiocyanate: :CH3S-C≡N → CH3N=C=S It is also prepared via with the reaction of methylamine with carbon disulfide followed by oxidation of the resulting dithiocarbamate with hydrogen peroxide. A related method is useful to prepare this compound in the laboratory.
|
|
Genetics Selection Evolution, 30(3), 1. Macrosynteny studies have determined that, in vocal learner birds, genes have undergone a deeper rearrangement along their corresponding chromosomes than those of non-vocal learner birds. In addition to that, microsynteny studies revealed that birds possess a higher number of orthologous genes that maintain synteny. This proves that gene order along chromosomes is more conserved in birds than in other animal groups.
|
|
The staircase was built during a major rearrangement and renovation of Kalemegdan Park. The concept design was done by Aleksandar Krstić, head of the parks department in the city administration, while the main project was work of Đorđe Kovaljevski. Main works were finished in 1928. During World War II, the staircase was damaged both during the German bombing of Belgrade in April 1941 and later during the war.
|
|
The fitting of shape and electric potential are the driving factor in this graphical approach. ;Molecular dynamics: Application of classical mechanics for simulating the movement of the nuclei of an assembly of atoms and molecules. The rearrangement of molecules within an ensemble is controlled by Van der Waals forces and promoted by temperature. ;Molecular mechanics: Modeling of the intra- and inter-molecular interaction potential energy surfaces via potentials.
|
|
The quasi-reverisible nature of the signal suggested that the complex then underwent further chemical rearrangement. Reduction using metallic potassium in THF produced a solution that changed color from dark blue to greenish-yellow over the course of the reaction. The yellow solid product was then isolated with 80% yield. The product was determined to be a three-coordinate six-membered cyclic silyene: an isomer of the parent silylone.
|
|
The scavenger can be any reagent that will irreversibly react with water such as phthalic anhydride or titanium chloride. The temperature required for the reaction varies based upon choice of acid and water scavenger. The yield of this reaction is much higher: at least 55%.Conversion of Morphine (I) to Apomorphine (II) in the presence of acid following the example of the morphine skeleton dehydration rearrangement, outlined by Bentley.
|
|
The 1995 CD Highlander: The Original Scores includes five cues from Kamen's Highlander score (along with six cues from Stewart Copeland's Highlander II score, and four cues from J. Peter Robinson's Highlander III score). Furthermore, a rearrangement of an excerpt from Kamen's score (specifically, the beginning of the track "The Quickening") was used as the theme music for New Line Cinema's logo ident in the late 1990s and early 2000s.
|
|
The opening and closing themes — "Curried Soul" and "Koff Drops", respectively — are played by Moe Koffman. The second segment of the show begins with a 1987 rearrangement of "Curried Soul" by Billy Bryans. In September 2013, amidst much on-air fanfare, the decades-old "Curried Soul" opening theme was given a discreetly modernized remix by Socalled."As It Happens 'Curried Soul' theme remixer Socalled on how to remix a classic" .
|
|
A 2009 phylogenetic analysis based on mitochondrial and nuclear DNA found otherwise, that this species was in fact basal to all other wobbegongs except the northern wobbegong (O. wardi). This result supports the synonymization of Eucrossorhinus with Orectolobus. Molecular clock estimation placed the speciation of the tasselled wobbegong at 11–6 Ma, coinciding with a period of significant geological rearrangement and the formation of coral reef habitats in the region.
|
|
The benzylic methylene proton is acidic and deprotonation takes place to produce the benzylic ylide (1). This ylide is in equilibrium with a second ylide that is formed by deprotonation of one of the ammonium methyl groups (2). Though the second ylide is present in much smaller amounts, it undergoes a 2,3-sigmatropic rearrangement and subsequent aromatization to form the final product (3).Ahluwalia, V. K., and R. K. Parashar.
|
|
In some cases, the full leg still grows, but in others it does not, although the frog may still live out its normal lifespan with only three limbs. Occasionally, a parasitic flatworm (Ribeiroia ondatrae) digs into the rear of a tadpole, causing a rearrangement of the limb bud cells and the frog develops one or more extra legs. Northern leopard frog (Rana pipiens) moulting and eating its skin.
|
|
The purpose of this relaxation is to allow compiler optimization to perform certain kinds of code rearrangement that preserve the semantics of properly synchronized programs. ;Interprocedural, whole-program or link-time optimization: These analyze all of a program's source code. The greater quantity of information extracted means that optimizations can be more effective compared to when they only have access to local information, i.e. within a single function.
|
|
The first synthesis of thiosulfinates was reported in 1947 by Cavallito and coworkers by oxidation of the corresponding disulfides. One example of a moderately stable thiosulfinate is the tert-butyl derivative, (CH3)3CS(O)SC(CH3)3. This thiosulfinate can be obtained in optical purity by catalytic asymmetric oxidation of di-tert-butyl disulfide with hydrogen peroxide. Upon heating, (CH3)3CS(O)SC(CH3)3 decomposes into tert- butanethiosulfoxylic acid (CH3)3CSSOH) as shown by trapping studies. In a similar manner racemic methyl methanethiosulfinate (CH3S(O)SCH3) can be obtained by peracetic acid oxidation of dimethyl disulfide. Methyl methanethiosulfinate decomposes thermally giving methanesulfenic acid (CH3SOH), the simplest sulfenic acid, as well as thioformaldehyde (CH2=S). Methyl methanethiosulfinate can also disproportionate to a 1:1 mixture of dimethyl disulfide and methyl methanethiosulfonate (CH3SO2SCH3) and rearrange via a Pummerer rearrangement to CH3S(O)CH2SSCH3. An unusual three-membered ring thiosulfinate (a dithiirane 1-oxide) has been prepared through rearrangement of a 1,3-dithietane.
|
|
The cytochrome P450s (P450s) are xenobiotic-metabolizing membrane- bound heme-containing enzymes that use molecular oxygen and electrons from NADPH cytochrome P450 reductase to oxidize their substrates. CYP2B4, a member of the cytochrome P450 family is the only protein within this family, whose X-ray structure in both open 11 and closed form 12 is published. The comparison of the open and closed structures of CYP2B4 structures reveals large-scale conformational rearrangement between the two states, with the greatest conformational change around the residues 215-225, which is widely open in ligand-free state and shut after ligand binding; and the region around loop C near the heme. HB Plot and structure of Cytochrome P450 2B4 in closed form Examining the HB plot of the closed and open state of CYP2B4 revealed that the rearrangement of tertiary hydrogen bonds was in excellent agreement with the current knowledge of the cytochrome P450 catalytic cycle.
|
|
According to the principle of original order, the originator's arrangement of the materials holds value, because it reflects how they originally used and accessed the collection, as well as how the records relate to each other, which can both inform the initial purpose of the records. Depending on the collection, rearrangement of the materials may not be required if a logical original order appears to have been maintained, the arrangement provides contextual clues about the purpose of the records and the arrangement does not interfere with researcher access to the materials. If rearrangement is required, archival processors will arrange the materials at the collection level, series level, subseries level, box level, folder level, or item level. The level of arrangement is determined by a number of factors, which include but are not limited to the orderliness of the material, the probable researcher interest and research value in the collection,[2] and the policy and resources of the repository.
|
|
Dievodiamine is a natural product from the plant Evodia rutaecarpa, which is widely used in traditional Chinese medicine. Unsworth et al.’s protecting group-free total synthesis of dievodiamine utilizes the Curtius rearrangement in the first step of the synthesis, catalyzed by boron trifluoride. The activated isocyanate then quickly reacts with the indole ring in an electrophilic aromatic substitution reaction to give the amide in 94% yield, and subsequent steps give dievodamine.
|
|
Heavy chain contains similar gene segments such as VH, JH and CH, but also has another gene segment called D (diversity). Unlike the light chain multigene family, VDJ gene segments code for the variable region of the heavy chain. The rearrangement and reorganization of gene segments in this multigene family is more complex . The rearranging and joining of segments produced different end products because these are carried out by different RNA processes.
|
|
Aggregate stability is one of indicators of soil quality, as it combines soil physical, chemical, and biological properties (Doran & Parkin, 1996). The formation of soil aggregates (or so-called secondary soil particles or peds) occurs due to interactions of primary soil particles (i.e., clay) through rearrangement, flocculation and cementation. Aggregate stability has a direct impact on soil pore size distribution, which affects soil water retention and water movement in soil, therefore affecting air movement.
|
|
In semibullvalene (C8H8), one ethylene arm is replaced by a single bond. The compound was first prepared by photolysis of barrelene in isopentane with acetone as a photosensitizer in 1966. Scheme 3. Semibullvalene synthesis Semibullvalene exists only as two valence tautomers (2a and 2b in scheme 3) but in this molecule the Cope rearrangement takes place even at -110 °C, a temperature at which this type of reaction is ordinarily not possible.
|
|
Article 16. In all works of preservation, restoration or excavation, there should always be precise documentation in the form of analytical and critical reports, illustrated with drawings and photographs. Every stage of the work of clearing, consolidation, rearrangement and integration, as well as technical and formal features identified during the course of the work, should be included. This record should be placed in the archives of a public institution and made available to research workers.
|
|
Human Cdc42 is a small GTPase of the Rho family, which regulates signaling pathways that control diverse cellular functions including cell morphology, cell migration, endocytosis and cell cycle progression. Rho GTPases are central to dynamic actin cytoskeletal assembly and rearrangement that are the basis of cell-cell adhesion and migration. Activated Cdc42 activates by conformational changes p21-activated kinases PAK1 and PAK2, which in turn initiate actin reorganization and regulate cell adhesion, migration, and invasion.
|
|
This rearrangement was originally encountered in the photolysis of barrelene to give semibullvalene. Once the mechanism was recognized as general by Zimmerman in 1967, it was clear that the structural requirement was having two pi groups attached to an sp3-hybridized carbon, and then a variety of further examples was obtained. One was the photolysis of the Mariano Compound, 3,3-methyl-1,1,5,5-tetraphenyl-1,4-pentadiene. Another was the reaction of the Pratt diene Equation 1.
|
|
Biosynthesis of atropine starting from L-Phenylalanine The biosynthesis of atropine starting from l-phenylalanine first undergoes a transamination forming phenylpyruvic acid which is then reduced to phenyl-lactic acid. Coenzyme A then couples phenyl-lactic acid with tropine forming littorine, which then undergoes a radical rearrangement initiated with a P450 enzyme forming hyoscyamine aldehyde. A dehydrogenase then reduces the aldehyde to a primary alcohol making (−)-hyoscyamine, which upon racemization forms atropine.
|
|
The specific epithet was chosen to honour the Austrian ornithologist August von Pelzeln (1825–1891). A molecular phylogenetic study published in 2013 found that the genus Myrmeciza was polyphyletic. In the resulting rearrangement to create monophyletic genera the grey-bellied antbird was moved to its own genus Ammonastes. The name of the genus combines the Ancient Greek words ammos "sand" and nastes "inhabitant" as the grey-bellied antbird occurs in vegetation growing on sandy soil.
|
|
Remington chaired the Museum's Committee on Architectural Rearrangement from 1941 to 1943. Composed of Museum curators and administrators, the Committee was tasked with surveying individual departments' existing storage, display, and conservation spaces to assist in future planning for Museum expansion. In the 1950s, Remington worked on the installation of the period rooms of the Museum, opened in 1954. Throughout his career, he published extensively in his Museum's journals on objects in its collection.
|
|
In this album, she performs scat singing, creates swing feeling, and the quintet plays in A-A-B-A form in some songs while fusing those techniques with other genres. One remarkable point other than her vocal jazz performance is her rearrangement of Korean traditional folk song Arirang. Na Yoon-Sun sang this jazz version of Arirang at Sochi Winter Olympic closing ceremony in 2014 celebrating South Korea's hosting of the next winter Olympic.
|
|
By placing an alcohol on the carbon on the reagent, reaction rates and yields are much improved to those of the simple Demjanov rearrangement. Moreover, few unwanted by products are formed, such as olefins. These aforementioned observations were the center around which Smith and Baer's mechanism was constructed. It is easy to see that hydrogen's presence would mean that hydride shifts would occur in competition with carbon shifts during the course of the reaction.
|
|
The reaction is catalyzed by nucleophiles such as a cyanide or an N-heterocyclic carbene (usually thiazolium salts). The reaction mechanism was proposed in 1903 by A. J. Lapworth. In the first step in this reaction, the cyanide anion (as sodium cyanide) reacts with the aldehyde in a nucleophilic addition. Rearrangement of the intermediate results in polarity reversal of the carbonyl group, which then adds to the second carbonyl group in a second nucleophilic addition.
|
|
Werner Tochtermann (2008) Werner Tochtermann (born May 30, 1934 in Pforzheim) is a German chemist and emeritus professor. From 1976 till his retirement in 1999 he was full professor of Organic Chemistry at the University of Kiel. His main areas of research were the chemistry of medium and large rings, the synthesis of cyclophanes, and the heteroquadricyclane→heteropin rearrangement, e.g. for the synthesis of oxepins from furans (known as Prinzbach–Tochtermann sequenceL.
|
|
The tropylium cation reacts with nucleophiles to form substituted cycloheptatrienes, for example: : + → Reduction by lithium aluminum hydride yields cycloheptatriene. Reaction with a cyclopentadienide salt of sodium or lithium yields 7-cyclopentadienylcyclohepta-1,3,5-triene: : + → + When treated with oxidising agents such as chromic acid, the tropylium cation undergoes rearrangement into benzaldehyde: : + → + + Many metal complexes of tropylium ion are known. One example is [Mo(η7-C7H7)(CO)3]+, which is prepared by hydride abstraction from cycloheptatrienemolybdenum tricarbonyl.
|
|
Recent taxonomic work has changed the entity the name Lespedeza violacea applies to. Based upon a reexamination of the type specimens, it was determined that Lespedeza violacea is the correct name of what was traditionally known as Lespedeza intermedia. The entity traditionally known as Lespedeza violacea now has the name Lespedeza frutescens. This nomenclature rearrangement has resulted in widespread confusion among botanists, with older references and some modern botanists retaining the traditional usage.
|
|
While the traditional Meyer–Schuster rearrangement uses harsh conditions with a strong acid as the catalyst, this introduces competition with the Rupe reaction if the alcohol is tertiary. Milder conditions have been used successfully with transition metal-based and Lewis acid catalysts (for example, Ru-Cadierno, V.; Crochet, P.; Gimeno, J. Synlett 2008, 1105–1124. () and Ag-basedSugawara, Y.; Yamada, W.; Yoshida, S.; Ikeno, T.; Yamada, T. J. Am. Chem. Soc. 2007, 129, 12902-12903.
|
|
An NIH shift is a chemical rearrangement where a hydrogen atom on an aromatic ring undergoes an intramolecular migration primarily during a hydroxylation reaction. This process is also known as a 1,2-hydride shift. These shifts are often studied and observed by isotopic labeling. An example of an NIH shift is shown below: Example of NIH shift In this example, a hydrogen atom has been isotopically labeled using deuterium (shown in red).
|
|
The reaction occurs by a rhodium acetate-catalyzed reaction between the aryldiazoacetate (red) and the organic azide (blue) to form an imine. A Wolff Rearrangement of the diazoacetoacetate enone (black) forms a stable ketene, which reacts with the imine to form a stable β-lactam compound. The solvent used for this reaction is dichloromethane (DCM) and the solution needs to rest for 3 hours at room temperature. The yield of the reaction is about 99%.
|
|
Science 132, 1497-1497 (1960) and of the resulting BCR-ABL1 fusion point to a different pathogenetic process. Since no specific recurrent genomic or karyotypic abnormalities have been identified in aCML, the molecular pathogenesis of this disease has remained elusive and the outcome dismal (median survival 37 months)Kurzrock, R. et al. BCR rearrangement-negative chronic myelogenous leukemia revisited. J Clin Oncol. 19, 2915-26 (2001). with no improvement over the last 20 years.
|
|
Formation of stannyldienals from Zincke aldehydes In 2009, the Vanderwal group reported another interesting rearrangement of Zincke aldehydes. Tryptamine-derived Zincke aldehydes are heated with strong base to give the rearranged enal as shown below. This reaction was the key step in their total synthesis of norfluorocurarine, a Strychnos alkaloid. This strategy was also employed in a short synthesis of strychnine, becoming the shortest synthesis of strychnine reported to date at only six linear steps.
|
|
Yeagle, Philip. The Structure of Biological Membranes. 2nd. ed. CRC Press, (2005). 173–194. For example, the strength of the intermolecular forces within the biomembrane are fairly strong but when lipids are extracted from biomembranes for analytical purposes there is a decrease in the constraints by the intermolecular forces against the phospholipids which may cause the lipid to undergo polymorphism as well as a temporary rearrangement of other lipids or proteins in the biomembrane.
|
|
George's and Thiele and Ladiges' positioning of B. spinulosa var. collina within B. spinulosa is supported, but B. spinulosa's placement is not. Series Spicigerae appears to be polyphyletic, with B. spinulosa and B. ericifolia more closely related to the taxa in Series Salicinae than it is to the other members of series Spicigerae. Early in 2007, Mast and Thiele initiated a rearrangement of Banksia by merging Dryandra into it, and publishing B. subg.
|
|
Eric Hattan departs from concrete objects and spaces. He questions places, architectures and situations of all-day-life through breaking regularities and subversing the assumed stasis of the world with playful irony. The rearrangement of clothing, furniture, pedestals or monitors plays a decisive role in his oeuvre, even became independent and exposes given situations to unbiased observation. Eric Hattan directs his gaze on processes and incidents in the urban space through his video camera.
|
|
With those credentials, he became a member of an expedition that worked on the rearrangement of the frontiers among Portuguese and Spanish colonies in South America. In 1753, he sailed for Brazil into the very mouth of the Amazon River. Based on his surveys, Lorenz Kaulen made in 1753 a map of Maranhão district titled Mappa Viceprovinciae Societatis Iesu Maragnonii anno MDCCLIII concinnata. Its original is in Biblioteca de Évora in Portugal.
|
|
The full HERC2 gene is located at 15q13, encoded by 93 exons and its transcription is under the control of a CpG rich promoter. This region on chromosome 15 is susceptible to breaks during chromosomal rearrangement and there are at least 12 partial duplicates of HERC2 between 15q11–15q13. At least 15 HERC2 SNPs have been identified and they are strongly associated with human iris colour variability, functioning to repress expression of OCA2's product.
|
|
Since 1998, Austin Mast has been publishing results of ongoing cladistic analyses of DNA sequence data for the subtribe Banksiinae. His analyses suggest a phylogeny that is very greatly different from George's taxonomic arrangement, including finding Banksia to be paraphyletic with respect to Dryandra. Early in 2007 Mast and Thiele initiated a rearrangement of Banksia by transferring Dryandra into it, and publishing B. subg. Spathulatae for the species having spoon-shaped cotyledons.
|
|
It has also allowed researchers to better understand genome evolution events - gene loss, gain, duplication, rearrangement - and how those events impact pathogen resistance and ability to cause disease. This influx of information has created a need for making the vast amounts of data accessible to researchers in the form of databases, and it has raised ethical questions about the wisdom of reconstructing previously extinct and deadly pathogens in order to better understand virulence.
|
|
This conformational rearrangement makes the serpin a more effective inhibitor. The archetypal example of this situation is antithrombin, which circulates in plasma in a partially inserted relatively inactive state. The primary specificity determining residue (the P1 arginine) points toward the body of the serpin and is unavailable to the protease. Upon binding a high-affinity pentasaccharide sequence within long-chain heparin, antithrombin undergoes a conformational change, RCL expulsion, and exposure of the P1 arginine.
|
|
Adapted from In the solvolysis of spiro-vinyl triflate, the formation of a vinyl cation intermediate through a concerted process drives further rearrangements that involve the formation of a completely different cyclic structure. Ring expansion can also be achieved through the rearrangement of a vinyl cation. 1,2-hydride shift in vinyl cation to form another vinyl cation isomer. Adapted from The second class of rearrangements, the vinyl cation rearranges to form another vinyl cation isomer.
|
|
Pyrmont Post Office, as it stands today, was completed in 1901. It is a two-storey sandstone building with basement, providing a Post Office area to the front half of the building and three-storey residence to the rear half. In the original front entry was altered with the rearrangement of the interior ground floor. Post boxes were installed in their current locations and the current entry door replaced an existing telephone booth.
|
|
A 1,2-rearrangement is an organic reaction where a substituent moves from one atom to another atom in a chemical compound. In a 1,2 shift the movement involves two adjacent atoms but moves over larger distances are possible. Skeletal isomerization is not normally encountered in the laboratory, but is the basis of large applications in oil refineries. In general straight-chain alkanes, are converted to branched isomers by heating in the presence of a catalyst.
|
|
Map of a land consolidation process, with each color representing the holdings of different cultivators before (above image) and after (below image) the process Land consolidation is a planned readjustment and rearrangement of fragmented land parcels and their ownership. It is usually applied to form larger and more rational land holdings. Land consolidation can be used to improve rural infrastructure and to implement developmental and environmental policies (improving environmental sustainability and agriculture).
|
|
Each nadu functioned as an agrarian production unit and comprised around ten villages and possibly one or two towns (). Raja Raja Chola I introduced an intermediate division named ) to centralise the administration of the state. Chola-mandalam was divided into ten which, through bifurcation and rearrangement, increased to fifteen by early 12th century. At the peak of their powers, the Chola country was divided into nine mandalams which included conquered regions such as Sri Lanka.
|
|
The Hofmann rearrangement is a decarbonylation reaction whereby an amide is converted to an amine by way of an isocyanate intermediate. It is usually carried out under strongly basic conditions. ::500px The reaction can also be carried out under mildly acidic conditions by way of the same intermediate using a hypervalent iodine compound in aqueous solution. An example published in Organic Syntheses is the conversion of cyclobutanecarboxamide, easily synthesized from cyclobutylcarboxylic acid, to cyclobutylamine.
|
|
Peierls predicted that the rearrangement of the ion cores in a Peierls transition would produce periodic fluctuations in the electron density. These are commonly called charge density waves, and they are an example of collective charge transport. Several materials systems have verified the existence of these waves. Good candidates are weakly coupled molecular chains, where electrons can move freely along the direction of the chains, but motion is restricted perpendicular to the chains.
|
|
The O-bonded isomer is often written as [Co(NH3)5(ONO)]2+. Although the existence of the isomers had been known since the late 1800s, only in 1907 was the structural difference explained. It was later shown that the red isomer converted to the yellow isomer upon UV-irradiation. In this particular example, the formation of the nitro isomer (Co-NO2) from the nitrito isomer (Co-ONO) occurs by an intramolecular rearrangement.
|
|
Amidophosphites and silyloxyphosphites have been used before to yield amidophosphonates and phosphinic acids. 424x424px An Arbuzov type rearrangement can also occur where the O from an OR group acts as the leaving group in the initial SN2 attack of the phosphorus. This is only known to occur when A and B are Cl. 228x228px Phosphite esters are the least reactive class of reagents used in this reaction. They react to produce phosphonates.
|
|
Indications of thermal rearrangements of aromatic hydrocarbons were first noted in the early 20th century by natural products chemists who were working with sesquiterpenes. At the time, they noticed the automerization of a substituted azulene shown below, but no further structural or mechanistic investigations were made. upright=1.5 The oldest characterized thermal rearrangement of an aromatic compound was that of the isomerization of azulene to naphthalene by Heilbronner et al. in 1947.
|
|
Whether the initial epimerization of trans substrates occurs via a one- or two-center process is unclear in most cases. (2)523px Transition-metal-catalyzed versions of the rearrangement are known, and mechanisms vary. In one example employing rhodium bis(ethylene) hexafluoroacetylacetonate, coordination and formation of a bis-π-allyl complex precede electrocyclic ring closure and catalyst release.Alcock, N. W.; Brown, J. M.; Conneely, J. A.; Stofko, Jr., J. J. J. Chem. Soc.
|
|
The most famous and commercially important reaction of cyclohexanone oxime is its Beckmann rearrangement yielding ε-caprolactam: : 300px This reaction is catalyzed by sulfuric acid, but industrial scale reactions use solid acids.Corma, Avelino; Garcia, Hermenegildo "Organic reactions catalyzed over solid acids" Catalysis Today 1997, volume 38, pp. 257-308. Typical of oximes, the compound can be reduced by sodium amalgam gives cyclohexylamine.W. H. Lycan, S. V. Puntambeker, and C. S. Marvel "n-Heptylamine" Org. Synth.
|
|
J. K.-Stift. Ver. Sozialanthropol. Ras. 11, 1-280. Classically, supergenes were hypothesized to have evolved from less tightly- linked genes coming together via chromosomal rearrangement or reduced crossing over, due to selection for particular multilocus phenotypes. For instance, in Batesian mimicry supergenes in species such as Papilio memnon, genes are required to affect hind-wing, fore-wing, and body colour, and also the presence or absence of long projections (the "tails" of swallowtail butterflies).
|
|
T cells have distinct T cell receptors. These distinct receptors are formed by process of V(D)J recombination gene rearrangement stimulated by RAG1 and RAG2 genes. This process is error-prone, and some thymocytes fail to make functional T-cell receptors, whereas other thymocytes make T-cell receptors that are autoreactive. If a functional T cell receptor is formed, the thymocyte will begin to express simultaneously the cell surface proteins CD4 and CD8.
|
|
Early in 2007 Mast and Thiele initiated a rearrangement by transferring Dryandra to Banksia, and publishing B. subg. Spathulatae for the species having spoon- shaped cotyledons; in this way they also redefined the autonym B. subg. Banksia. They foreshadowed publishing a full arrangement once DNA sampling of Dryandra was complete; in the meantime, if Mast and Thiele's nomenclatural changes are taken as an interim arrangement, then B. media is placed in B. subg. Banksia.
|
|
Along with single cell migration, collective cell migration can occur when groups of firmly interconnected tumor cells are migrating. This type of migration indicates tissue rearrangement, underlies the processes of embryonic morphogenesis, and also is an essential component in the healing of wound surfaces. Therefore, the key is that malignant tumor cells extensively use the mechanisms of both collective and single cell migration as physiological prototypes in the process of invasive growth and metastasis.
|
|
Early in 2007 Mast and Thiele initiated a rearrangement by transferring Dryandra to Banksia, and publishing B. subg. Spathulatae for the species having spoon-shaped cotyledons; in this way they also redefined the autonym B. subg. Banksia. They foreshadowed publishing a full arrangement once DNA sampling of Dryandra was complete; in the meantime, if Mast and Thiele's nomenclatural changes are taken as an interim arrangement, then B. praemorsa is placed in B. subg. Banksia.
|
|
Occidentales, a subseries of B. ser. Spicigerae. Early in 2007, Mast and Thiele initiated a rearrangement of Banksia by merging Dryandra into it, and publishing B. subg. Spathulatae for the taxa having spoon-shaped cotyledons. They foreshadowed publishing a full arrangement once DNA sampling of Dryandra was complete; in the meantime, if Mast and Thiele's nomenclatural changes are taken as an interim arrangement, then B. nutans is placed in B. subg. Spathulatae.
|
|
Young received her B.S. and M.S. from Wake Forest University, working with Prof. Huw Davies. She was co-author on an early application of Davies' rhodium(II) carbenoid insertion - Cope rearrangement chemistry, leading to the total synthesis of three small tropane natural products. Young received her Ph.D. from Princeton in 1993, working with Edward C. Taylor on heterocycles derived from natural pigments, one of which ultimately became pemetrexed (Alimta), an oncology treatment.
|
|
A derivative chromosome (der) is a structurally rearranged chromosome generated either by a chromosome rearrangement involving two or more chromosomes or by multiple chromosome aberrations within a single chromosome (e.g. an inversion and a deletion of the same chromosome, or deletions in both arms of a single chromosome). The term always refers to the chromosome that has an intact centromere. Derivative chromosomes are designated by the abbreviation der when used to describe a Karyotype.
|
|
A new taxonomic arrangement was not published at the time, but early in 2007 Mast and Thiele initiated a rearrangement by transferring Dryandra to Banksia, and publishing B. subg. Spathulatae for the species having spoon- shaped cotyledons. They foreshadowed publishing a full arrangement once DNA sampling of Dryandra was complete; in the meantime, if Mast and Thiele's nomenclatural changes are taken as an interim arrangement, then B. spinulosa is placed in B. subg. Spathulatae.
|
|
Imprinting is defined as the differential expression of paternal and maternal alleles of a gene, due to epigenetic marks introduced onto the chromosome during the production of egg and sperm. These marks usually lead to differential expression of the specific sets of genes from the maternal and paternal chromosomes. Imprinting is carried out through many epigenetic mechanisms like methylation, histone modifications, rearrangement of higher order chromatin structure, non-coding RNAs, and interfering RNAs.
|
|
In an experiment, fine-tiling comparative genomic hybridization (FT-CGH) and ligation-mediated PCR (LM-PCR) were combined. This resulted in the finding of a chromosomal translocation t(12;14)(q23;q11.2) in T-lymphoblastic lymphoma (T-LBL). The chromosomal translocation occurs during T-receptor delta gene-deleting rearrangement, which is important in T-cell differentiation. This translocation disrupts C12orf42 and it brings the gene ASCL1 closer to the T-cell receptor alpha (TRA) enhancer.
|
|
Károlyi, Bedő (2002) The carved foundations of the baldachin's columns were removed, and they were replaced by taller, but really simple, cuboid parts. To provide enough space for the priests, a new, smaller altar table was erected under the baldachin. The table was also turned around with its longer side parallel to the iconostasis. The result of this rearrangement was that the baldachin didn't really fit to the table itself, it was wider than needed.
|
|
The study of these questions belongs to number theory. Goldbach's conjecture is an example of a still unanswered question: "Is every even number the sum of two primes?" One answered question, as to whether every integer greater than one is a product of primes in only one way, except for a rearrangement of the primes, was confirmed; this proven claim is called the fundamental theorem of arithmetic. A proof appears in Euclid's Elements.
|
|