Catalytic enantioselective and divergent total synthesis of (+)-10-oxocylindrocarpidine, (+)-cylindrocarpidine, (-)-N-acetylcylindrocarpinol, and (+)-aspidospermine.

The catalytic enantioselective and divergent total syntheses of Aspidosperma alkaloids (+)-10-oxocylindrocarpidine 7, (+)-cylindrocarpidine 1, (-)-N-acetylcylindrocarpinol 6, and (+)-aspidospermine 8 have been accomplished in 11 steps from a common precursor (15) on the basis of a highly concise route. The route features three metal-catalyzed reactions, including the key Pd-catalyzed decarboxylative asymmetric allylation of carbazolones developed in our laboratory. Our syntheses, using a combination of C-H activation, enantioselective catalysis, and collective synthesis, represent the first total synthesis of 10-oxocylindrocarpidine and the first asymmetric total synthesis of cylindrocarpidine and N-acetylcylindrocarpinol.