Benz[b]indeno[2,1-e]pyran,dione 1a and analogues have been prepared and studied for enhancing the biosynthesis of erythropoietin. The scope of the Baker–Venkataraman rearrangement is illustrated by way of numerous examples of its application, and in doing so, the review contains over. This rearrangement reaction proceeds via enolate formation followed by acyl transfer. It is named after the scientists Wilson Baker and K. Venkataraman.
|Published (Last):||13 January 2007|
|PDF File Size:||11.70 Mb|
|ePub File Size:||19.24 Mb|
|Price:||Free* [*Free Regsitration Required]|
There was a problem providing the content you requested
The Baker—Venkataraman rearrangement is the chemical reaction of 2-acetoxyacetophenones with base to form 1,3-di ketones. This rearrangement reaction proceeds via enolate formation followed by acyl transfer. It is named after the scientists Wilson Baker and K.
The Baker—Venkataraman rearrangement is often used in the synthesis of chromones and flavones. After the base-catalyzed rearrangement, treatment with acid generally rearranggement the chromone or flavone core, though other milder reaerangement have been reported. A base abstracts the hydrogen atom alpha to the aromatic ketoneforming 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 phenolatewhich is protonated during acidic work-up to give the desired product. To complete the construction of the chromone or flavone core, cyclodehydration is required.
This was commonly afforded by treatment with strong acid, however many milder conditions have now been developed. One proposed mechanism for this dehydration is as follows:.
The Baker—Venkataraman rearrangement is the chemical reaction of 2-acetoxyacetophenones with base to form 1,3-diketones.
The cyclic intermediate is opened up to form a more stable phenolate, which is protonated during acidic work-up to give the desired product. This was commonly afforded by treatment with strong acid He was known for the demonstration of an organic chemical reaction involving 2-acetoxyacetophenones which later came to be known as the Baker—Venkataraman rearrangement and for his contributions in developing NCL into one of the leading research centres in organic chemistry.
The Government of India awarded him the Padma Bhushan, the third highest Indian civilian award, in Wilson entered Victoria University of Manchester at the age of 16, and having spent some time in France as a Quaker volunteer during the First World War graduated top of the honours class in He then undertook a M.
This was awarded in Venkataraman, Venkatraman and Venkitaraman are names of Indian origin, used both as family names and as masculine given names.
People with those names include: Family name Ashok Venkitaraman born beforeBritish cancer researcher C. Venkataraman —94Indian mathematician G. Venkataraman —98Indian botanist and academic administrator Ganesh Venkatraman active fromIndian film actor Ganeshan Venkataraman bornIndian physicist, writer and academic administrator Janaki Venkataraman —First Lady of India —92, wife of R.
Padma, bornIndian author of children’s books R. Venkataraman Ramaswamy Venkataraman, —Indian lawyer, independence activist and politician, President of India —92 S. Venkatraman —98Indian film actor, singer, and music director T. Venkataraman activeIndian politician Trivandrum R. Venkataraman —classical Indian musician and Well-known reactions and reagents in organic chemistry include 1,3-Dipolar cycloaddition 2,3-Wittig rearrangement A Abramovitch—Shapiro tryptamine synthesis Acetalisation Acetoacetic ester condensation Achmatowicz reaction Acylation Acyloin condensation Adams catalyst Adams decarboxylation Adkins catalyst Adkins—Peterson reaction Akabori amino acid reaction Alcohol oxidation Alder ene reaction Alder—Stein rules Aldol addition Aldol condensation Algar—Flynn—Oyamada reaction Alkylimino-de-oxo-bisubstitution Alkyne trimerisation Alkyne zipper reaction Allan—Robinson reaction Allylic rearrangement Amadori rearrangement Amine alkylation Angeli—Rimini reaction Andrussov oxidation Appel reaction Arbuzov reaction, Arbusow reaction Arens—van Dorp synthesis, Isler modification Gearrangement nitration Arndt—Eistert synthesis Auwers synthesis Azo coupling B Baeyer—Drewson indigo synthesis Baeyer—Villiger oxidation Baeyer—Villiger rearrangement Bakeland process Bakelite The following outline is provided as an overview of and topical guide to organic chemistry: Organic chemistry — scientific study of the structure, properties, composition, reactions, and preparation by synthesis or by other means of carbon-based compounds, hydrocarbons, and their derivatives.
These compounds may contain any number of other elements, including hydrogen, nitrogen, oxygen, the halogens as well as phosphorus, silicon, and sulfur. The Kostanecki acylation is a method used in organic synthesis to form chromones or coumarins by acylation of O-hydroxyaryl ketones with aliphatic acid anhydrides, followed by cyclization.
Mechanism The mechanism consists of three well-differentiated reactions: A Valid Scaffold in Medicinal Chemistry”. The Allan—Robinson reaction is the chemical reaction of o-hydroxyaryl ketones with aromatic anhydrides to form flavones or isoflavones. See Kostanecki acylation Reaction Overview Mechanism The first step is an enolization which is a proton transfer created a hydroxide instead of a carbonyl and an alkene instead of an alkane.
The second step is an acylation in which the newly formed bond from the enolization attacks an electrophilic carbon in rearrangemeng anhydride.
The third step displays the carboxylate functionality leaving since it is the best leaving group. venjataraman
As a result the resulting carboxylate attacks an alpha hydrogen to create the enol functionality again in step four. The fifth step shows the nucleophilic hydroxide attacking the carbonyl carbon to create a new six membered heterocyclic ring. The resulting structure undergoes a proton transfer in step 6 to achieve the final product. All six of these steps occur in the reacti Nucleophilic acyl substitution describe a class of substitution reactions involving nucleophiles and acyl compounds.
In this type of reaction, a haker — such as an alcohol, amine, or enolate — displaces the leaving group of an acyl derivative — such as an acid gaker, anhydride, or ester. The resulting product is a carbonyl-containing compound in which the nucleophile has bajer the place of the leaving venjataraman present in the original acyl derivative.
Because acyl derivatives react with a wide variety of nucleophiles, and because the product can depend on the particular type of acyl derivative and nucleophile involved, nucleophilic acyl substitution reactions can be used to synthesize a variety of different products.
Reaction mechanism Carbonyl compounds react with nucleophiles via an addition mechanism: This reaction can be accelerated by acidic conditions, which make the carbonyl more electrophilic, or basic conditions, wh Action of sodamide on 1-acyloxyacetonaphthones”.
Baker–Venkataraman rearrangement | Revolvy
Carbamoyl rendition of the Baker-Venkataraman rearrangement. Regiospecific route to substituted 4-hydroxycoumarins”. Total synthesis by carbamoyl Baker-Venkataraman rearrangement and structural revision to isoeugenetin methyl ether”. Baker—Venkataraman rearrangement topic The Baker—Venkataraman rearrangement is the chemical reaction of 2-acetoxyacetophenones with base to form 1,3-diketones.
Member feedback about Baker—Venkataraman rearrangement: Name reactions Revolvy Brain revolvybrain. Member feedback about Flavones: Flavones Revolvy Brain revolvybrain. Member feedback about Krishnasami Venkataraman: Member feedback about Wilson Baker: English chemists Revolvy Brain revolvybrain. Venkataraman topic Venkataraman, Venkatraman and Venkitaraman are names of Indian origin, used both as family names and as masculine given names.
Member feedback about Venkataraman: Disambiguation pages with given-name-holder lists Revolvy Brain revolvybrain. Member feedback about List of organic reactions: Outline of organic chemistry topic The following outline is provided as an overview of and topical guide to organic chemistry: Member feedback about Outline of organic chemistry: Organic chemistry Revolvy Brain revolvybrain peptide Lailakafu.
Kostanecki acylation topic The Kostanecki acylation is a method used in organic synthesis to form chromones or coumarins by acylation of O-hydroxyaryl ketones with rearrangeemnt acid anhydrides, followed by cyclization.
Member feedback about Kostanecki acylation: Organic reactions Revolvy Brain revolvybrain.
Allan—Robinson reaction topic The Allan—Robinson reaction is the chemical reaction of o-hydroxyaryl ketones with aromatic anhydrides to form flavones or isoflavones. Member feedback about Allan—Robinson venktaaraman Nucleophilic acyl substitution topic Nucleophilic acyl substitution describe a class of substitution reactions involving nucleophiles and acyl compounds.
Member feedback about Nucleophilic acyl substitution: Chemical reactions Revolvy Brain revolvybrain.