Phosphole sulfide 1 undergoes cycloaddition to give a new 15-phosphasteroid. The 13C- NMR and 2JPC-coupling constants of several compounds prepared similarly are discussed, permitting structure assignment to one of the 7-phosphabicyclo [2.2. 1] heptane adduct 5. Thiophosgene reacts with the P S moiety of 1, giving 12 after hydrolysis, through a P S to P O transformation coupled in case of 1 with a proton migration.
