New general synthesis of α-alkoxyketones via α′-alkylation, α-alkylation and α,α′-dialkylation of α-alkoxyketimines

Abstract

α-Methoxy- and α-ethoxyketones, as important intermediates in organic synthesis and flavor compounds in food chemistry, were synthesized by deprotonation of N-(1-alkoxy-2-propylidene)isopropylamine, prepared by condensation of the corresponding α-alkoxyacetone with isopropylamine, and subsequent reaction of the corresponding 1-azaallylic anions with alkyl halides to afford α′-alkylated, α-alkylated and α,α′-dialkylated ketimines. Hydrolysis of the imino function led to the desired substituted α-alkoxyketones. The ratio of α-, α′-, and α,α′-(di)alkylated compounds depended on the amount of base used and on the nature of the alkylating reagent.