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claisen-condensation. RSC ontology ID. RXNO:0000043. The Claisen condensation is a carbon–carbon bond forming reaction that occurs between two esters or one ester and another carbonyl compound in the presence of a strong base. The reaction produces a β-keto ester or a β- diketone. [1] It is named after Rainer Ludwig Claisen, who first ...
Claisen–Schmidt condensation. In organic chemistry, the Claisen–Schmidt condensation is the reaction between an aldehyde or ketone having an α-hydrogen with an aromatic carbonyl compound lacking an α-hydrogen. It can be considered as a specific variation of the aldol condensation. This reaction is named after two of its pioneering ...
The Claisen rearrangement is a powerful carbon–carbon bond-forming chemical reaction discovered by Rainer Ludwig Claisen. [1] The heating of an allyl vinyl ether will initiate a [3,3]-sigmatropic rearrangement to give a γ,δ-unsaturated carbonyl, driven by exergonically favored carbonyl CO bond formation (Δ(Δ f H) = −327 kcal/mol (−1,370 kJ/mol).
chemistry. Rainer Ludwig Claisen (German pronunciation: [ˈʁaɪnɐ ˈklaɪzn̩]; 14 January 1851 – 5 January 1930) was a German chemist best known for his work with condensations of carbonyls and sigmatropic rearrangements. He was born in Cologne as the son of a jurist and studied chemistry at the university of Bonn (1869), where he became a ...
In the Claisen condensation, an enolate of one ester (1) will attack the carbonyl group of another ester (2) to give tetrahedral intermediate 3. The intermediate collapses, forcing out an alkoxide (R'O −) and producing β-keto ester 4. The Claisen condensation involves the reaction of an ester enolate and an ester to form a beta-keto ester.
The Dieckmann condensation is the intramolecular chemical reaction of diesters with base to give β-keto esters. [1] It is named after the German chemist Walter Dieckmann (1869–1925). [2][3] The equivalent intermolecular reaction is the Claisen condensation. Dieckmann condensations are highly effective routes to 5-, 6-, and 7-member rings ...
The ACP-bound elongation group reacts in a Claisen condensation with the KS-bound polyketide chain under CO 2 evolution, leaving a free KS domain and an ACP-bound elongated polyketide chain. The reaction takes place at the KS n -bound end of the chain, so that the chain moves out one position and the elongation group becomes the new bound group.
Fatty acid synthase. Fatty acid synthase (FAS) [1] is an enzyme that in humans is encoded by the FASN gene. [2][3][4][5] Fatty acid synthase is a multi-enzyme protein that catalyzes fatty acid synthesis. It is not a single enzyme but a whole enzymatic system composed of two identical 272 kDa multifunctional polypeptides, in which substrates are ...