The Aldol Condensation

Nielsen, Arnold T.; Houlihan, William J.


The aldol condensation takes its name from aldol (3-hydroxybutanal) a name introduced by Wurtz who first prepared the beta-hydroxy aldehyde from acetaldehyde in 1872. The aldol condensation includes reactions producing beta-hydroxy aldehydes or beta-hydroxy ketones by self condensations or mixed condensations of aldehydes and ketones as well as reactions leading to alpha, beta-unsaturated aldehydes or alpha,beta-unsaturated ketones formed by dehydration of intermediate beta-aldols or beta-ketals. The Claisen-Schmidt condensation is most often taken to be the condensation of an aromatic aldehyde or ketone usually in the presence of a basic catalyst. The term aldol condensation has also been applied to many other condensations involving the reaction of an aldehyde or ketone. These condenations are discussed. The present review includes examples that are solely condensation reactions of aldehydes and ketones.