Highly regioselective rearrangement of 2-substituted vinylepoxides catalyzed by gallium(III) triflate.

Gallium(III) triflate catalyzed the rearrangement of 2-substituted vinylepoxides into beta,gamma-unsaturated carbonyl compounds with high regio- and chemoselectivity (>97/3) in low catalyst loading (1-5 mol %). The alkyl-substituted trimethylsilylvinyl epoxides gave beta,gamma-unsaturated ketone, but aryl-substituted vinylepoxides gave the aldehydes instead.