Synthesis of α‐Substituted Succinimides from Glyoxal and Ketene N,S‐Acetals

Abstract

The reaction of ketene N,S-acetals with glyoxal for the efficient synthesis of α-ketosuccinimides is described. Promoted by concentrated hydrobromide, the reaction proceeded under mild aqueous, metal-free conditions, with broad substrate tolerance. As a result, one CÀ C, one CÀ N, and one CÀ O bond were formed. Mechanistic studies show that this tandem process involves enamine addition, hydrolysis and intramolecular nucleophilic addition. In the proposed mechanism, the amine released as a byproduct plays a promoter role to accelerate the construction of α-ketosuccinimides.[a] Q.