Epoxidation versus Allylic Oxidation (CH Insertion) in the Oxyfunctionalization of Vinylsilanes and β-Hydroxy Derivatives by Dimethyldioxirane.

Abstract Epoxidation of acyclic vinylsilanes by dimethyldioxirane affords α,β-epoxysilanes in high yields, whereas for cyclic vinylsilanes appreciable amounts of allylic oxidation is observed. These competitive pathways become more pronounced, when the reactivity of the double bond is decreased by electronic and/or steric factors.