Efficient synthesis of alpha,beta-epoxy carbonyl compounds in acetonitirile: Darzens condensation of aromatic aldehydes with ethyl chloroacetate

摘要

The Darzens reaction of ethyl 2-chloroacelate (1) with aromatic aldehydes 2 in the presence of polymer-supported or nonsupported quaternary ammonium salts proceeds under mild conditions by phase-transfer catalysis to give the corresponding epoxides 3 in satisfactory yields (Tables 7 and 2). With both McCN as solvent and polystyrene-supported catalysts, diastereoselective Darzens reactions proceed in excellent yields and short times, with a fair degree of stereoinduction.