Synthesis of 6,19-sulfamidate bridged pregnanes

Conformationally restrained substituted pregnane-20-one derivatives are obtained by an intramolecular nitrene and dition onto a C-5/C-6 double bond involving a tethered C-19 sulfamoyl moiety. The resulting aziridine underwent regioselective nucleophilic ring opening at C-5 at room temperature with cyanide, fluoride, and acetate.