The Michael Addition of Aliphatic Aldimines to Methyl Vinyl Ketone

Abstract

The Michael addition of N- (2, 2-dialkylethylidene) -t -butylamines to methyl vinyl ketone took place smoothly to produce 5, 5-dialkyl-6- (t-butylimino) -2-hexanones in 8997 % yields.
Treatment of the adducts with equimolar amount of hydrochloric acid afforded 2, 2-dialkyl-5-oxhexanals in 8393 % yields, while treatment with excess hydrochloric acid gave 4, 4-dialkyl-2-cyclohexen-1-ones in 8297 % yields. In the case of the imines derived from dialkylacetaldehydes and straight chain amines, the Michael addition, was accompanied by ring formation, leading to the mixtures of N- (4, 4-dialkyl-2-cyclohexenylidene) alkylamines and 4, 4-dialkyl-2-cyclohexen-1-ones. N-Propylidene- and N-butylidene-t-butylamine gave 5-methyl- and 5-ethyl-5- (t-butyliminomethyl) -2, 8-nonanedione, which on treatment with equimolar amount of hydrochloric acid gave the corresponding aldehydes.