A mild new procedure for production, cyclization and trapping of amidyl radicals: application to a formal total synthesis of peduncularine

Treatment of an olefinic hydroxamic acid with tert-butylsulfinyl chloride and Hunig’s base from −50°C to room temperature in the presence of a radical trap such as diphenyl diselenide, diphenyl disulfide or TEMPO affords a functionalized product derived from an amidyl radical cyclization. The methodology has been used in a formal total synthesis of the 6-azabicyclo[3.2.1]octane-containing indole alkaloid peduncularine.