Double Reduction of Cyclic Aromatic Sulfonamides: Synthesis of (+)-Mesembrine and (+)-Mesembranol

The synthesis of (+)-mesembrine (1) and (+)-mesembranol (2) has been achieved from the monoterpene (S)-(−)-perillyl alcohol. Key transformations include a diastereo- and regioselective Pd-mediated intramolecular Heck reaction, and a double reduction of the resultant cyclic sulfonamide, to afford the cis-3a-aryloctahydroindole skeleton.