Epoxy-Annulations by Reactions of α-Amido Ketones with Vinyl Sulfonium Salts. Reagent versus Substrate Control and Kinetic Resolution

Diphenyl vinyl sulfonium salt and chiral amido-ketones undergo highly diastereoselective epoxy-annulation reactions in good yield. The use
of a chiral vinyl sulfonium salt dominates the stereochemical outcome of the annulation reaction (reagent control is greater than substrate
control), and this has allowed the kinetic resolution of racemic amido-ketones to be achieved.