A General, One-Step Synthesis of α-Keto Esters

Abstract

Several new multi-step methods for the synthesis of α-keto esters have been reported recently which are based on the addition of alkyl lithium reagents to triethoxyacetonitrile¹, the reaction of Grignard reagents with ethy1 α-oxo-1H-imidazole-1-acetate², the alcoholysis of acy1 cyanides³, the acylation of mercaptal anions with ethy1 chloroformate⁴, the alkylation of 1,3-dithiane-2-carboxylate under homogeneous⁵ or under phase transfer conditions⁶ and the addition of the methyl methylthiomethyl sulfoxide anion to nitriles⁷. These novel methods lack the convenience of the direct addition of Grignard reagents to diethyl oxalate: