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 1a derived from pinacolone. Subsequent alkylation with alkyl halides led to ketene dithioacetal S-oxides in good to excellent yields.