Asymmetric synthesis of trans-2,5-disubstituted pyrrolidines from enantiopure homoallylic amines. Synthesis of pyrrolidine (-)-197

An iodocyclization of sulfinimine-derived enantiopure homoallylic sulfonamides that represents a valuable new route for the asymmetric synthesis of trans-2,5-disubstituted pyrrolidines is described. The homoallylic sulfonamides were prepared from readily available sulfinimine-derived beta-amino aldehydes using the Wittig reaction and were obtained as E:Z mixtures.