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The Dieckmann condensation, where a molecule with two ester groups reacts intramolecularly, forming a cyclic β-keto ester. In this case, the ring formed must not be strained, usually a 5- or 6-membered chain or ring. Retro-Claisen condensation is the reverse of the title reaction, i.e., the base-induced cleavage of 2-ketoesters
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).
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.
Claisen condensation; Claisen rearrangement; Claisen–Schmidt condensation; Clemmensen reduction; Collins reagent; Combes quinoline synthesis; Conia reaction; Conrad–Limpach synthesis; Cook–Heilbron thiazole synthesis; Cope elimination; Cope rearrangement [24] Corey reagent; Corey–Bakshi–Shibata reduction; Corey–Fuchs reaction; Corey ...
Claisen may refer to: Rainer Ludwig Claisen, a German chemist Claisen rearrangement, a reaction of a allyl vinyl ether to a γ,δ-unsaturated carbonyl; Claisen condensation, a reaction between esters and carbonyl compounds in the presence of a strong base; Ireland–Claisen rearrangement, a chemical reaction of an allylic ester with strong base
An important product of the Fischer-Fink synthesis was ethyl 4,5-dimethylpyrrole-2-carboxylate, made from ethyl 2-oximinoacetoacetate and 2-methyl-3-oxobutanal, in turn made by the Claisen condensation of 2-butanone with ethyl formate. [12]
The reaction is known as the Claisen reaction and was described by Claisen for the first time in 1890. Discovered the thermally induced rearrangement of allyl phenyl ether in 1912. He details its reaction mechanism in his last scientific publication (1925). In his honor, the reaction has been named the Claisen rearrangement.
It can be considered as a specific variation of the aldol condensation. This reaction is named after two of its pioneering investigators Rainer Ludwig Claisen and J. Gustav Schmidt, who independently published on this topic in 1880 and 1881. [1] [2] [3] An example is the synthesis of dibenzylideneacetone ((1E, 4E)-1,5-diphenylpenta-1,4-dien-3 ...