The nucleophilic epoxidation of simple (γ-silyloxy)vinyl sulfoxides takes place with completestereocontrol and high yields. For substrates bearing an additional substituent at the γ position,a reinforcing/nonreinforcing scenario is operative. While E and Z silylated substrates undergo aprimarily sulfur directed epoxidation with good to excellent diastereocontrol, the related (E)-(2-methoxyethoxy)methyl ethers display diminished selectivity for the diastereomer derived from thenonreinforcing scenario.
