Enantioselective Epoxidation of α,β-Unsaturated Ketones by Phase-Transfer Catalysis Using Chiral Quaternary Ammonium Salts

The catalytic enantioselective epoxidation promoted by quaternary ammonium salt as a phase transfer catalyst is described. Treatment chalcone derivatives with sodium hypochlorite under mild reaction conditions afforded the corresponding epoxy ketones in good yields with good to moderate enantiomeric excesses.