Synthesis of some electron-rich aryl(hetaryl)oxiranes under phase-transfer and homogeneous conditions

Reactions of mono-, di-, and trimethoxybenzaldehydes with trimethylsulfonium methyl sulfate readily occur under mild homogeneous and heterogeneous phase-transfer conditions to give the corresponding aryloxiranes whose yields are comparable with those typical of severe Corey-Chaykovsky reaction conditions. The phase-transfer version ensures better purity of the epoxy derivatives and is the only possible way of preparing 1-methyl-3-(oxiran-2-yl)-1H-indole.