Asymmetric synthesis of α,β-epoxysulfones under phase-transfer catalyzed Darzens reaction

Enantioselective synthesis of alpha,beta-epoxysulfones by the Darzens reaction was achieved under phase-transfer catalyzed conditions. The reaction of chloromethyl phenylsulfone with various aromatic aldehydes smoothly proceeded in the presence of a catalytic amount (10 mol %) of chiral quaternary ammonium salt derived from quinine with KOH at room temperature to afford the desired coupling products in good yield with up to 81% ee. (C) 1998 Elsevier Science Ltd. All rights reserved.