Alkene Difunctionalization Via b-Haloalkoxysulfonium Ions
Recently, we reported that halogen cations stabilized by dimethyl sulfoxide (DMSO) were successfully generated and accumulated in solution by low-temperature electrochemical oxidation. Reactions of DMSO-stabilized halogen cations such as Br+ and I+ with alkenes gave b-haloalkoxysulfonium ions. Subsequent treatment of the b-haloalkoxysulfonium ions with triethylamine gave α-halocarbonyl compounds via Swern−Moffatt type oxidation. Here, we report that treatment of the b-haloalkoxysulfonium ions with different bases gives different products, i.e. the use of sodium hydroxide and sodium methoxide gives halohydrins and epoxides, respectively.