2-Hydroxymalonitrile——A Useful Reagent for One-step Synthesis of α-Hydroxy Esters

α-Hydroxy carboxylic esters and their derivatives are key substructures in a variety of biologically active natural products and numerous pharmaceuticals[1-3].A variety of methods for the synthesis of α-hydroxyesters via homologation of aldehydes or ketones have been developed and frequently used in organic synthesis[4-14].These approaches are generally based on the following routes(Scheme 1).