Reactions of α-monochloro- and α,α-dichloro-β-oxoaldehyde acetals with bases

Abstract

α,α-Dichloro-β-oxoaldehyde diethyl acetals decompose under the action of bases (NaOH, MeONa) with cleavage of the carbon-carbon bond and formation of carboxylic acids or their esters and the dichloroacetaldehyde diethyl acetal carbanion. The latter reactsin situ with benzaldehyde to form stable α-chloro-α,β-epoxyacetal. α-Chloro-α-formyl-γ-butyrolactone diethyl acetal is transformed into α-chloro-α-diethoxymethyl-γ-hydroxybutyric acid under the action of an alkali.