Claisen–Schmidt condensation explained

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 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-one).^[4]

Quantitative yields in Claisen–Schmidt reactions have been reported in the absence of solvent using sodium hydroxide as the base and plus benzaldehydes.^[5] Because the enolizable nucleophilic carbonyl compound and the electrophilic carbonyl compound are two different chemicals, the Claisen–Schmidt reaction is an example of a crossed aldol process.

References

1. Claisen, L. . Claparède, A. . Condensationen von Ketonen mit Aldehyden . Condensations of ketones with aldehydes . . 1881 . 14 . 1 . 2460–2468 . 10.1002/cber.188101402192 .
2. Schmidt, J. G. . Ueber die Einwirkung von Aceton auf Furfurol und auf Bittermandelöl in Gegenwart von Alkalilauge . On the effect of acetone on furfural and on bitter almond oil (benzaldehyde) in the presence of alkali hydroxides . . 1881 . 14 . 1 . 1459–1461 . 10.1002/cber.188101401306 .
3. Book: March, J. . Advanced Organic Chemistry: Reactions, Mechanisms and Structure . 1985 . 3rd . Wiley Interscience . 0-471-85472-7 .
4. The Dibenzalacetone Reaction Revisited . Hull, L. A. . February 2001 . . 78 . 2 . 226 . 10.1021/ed078p226 . 2001JChEd..78..226H .
5. 10.3390/molecules17010571 . 17 . A Facile Solvent Free Claisen-Schmidt Reaction: Synthesis of α,α′-bis-(Substituted-benzylidene)cycloalkanones and α,α′-bis-(Substituted-alkylidene)cycloalkanones . 2012 . Molecules . 571–583 . Rahman A. F. M. Motiur, Ali Roushown, Jahng Yurngdong, Kadi Adnan A.. 1 . 22231494 . 6269007 . free .