Effects of additional stereogenic centres and cation in the nucleophilic epoxidation of vinylsulfoximines with metal alkylperoxides

Abstract Epoxidation of vinylsulfoximines using metal alkylperoxides proceeds with varying degrees of stereoselectivity, depending both on the metal cation and the steric bulk of the alkyl group. The stereochemical outcome of the epoxidation of substrates bearing an allylic asymmetric centre is also dependent on the epoxidising agent, and very high levels of stereoselectivity may be obtained in the formation of sulfonyloxirane 6a . This oxirane was subsequently converted into the sulfonyloxirane 13 , a precursor to a useful chiral functionalised acyl anion equivalent.