Highly chemoselective oxidation of dithioester enethiolates to sulfenates:: Application to the synthesis of ketene dithioacetal S-oxides

Enethiolates derived from dithioesters were efficiently converted into the corresponding vinyl sulfenates by oxidation with a unique N-sulfonyloxaziridine la derived from pinacolone. Subsequent alkylation with alkyl halides led to ketene dithioacetal S-oxides in good to excellent yields.