Total Synthesis of (−)-Aspidospermidine via\nan Enantioselective Palladium-Catalyzed Allylic Substitution Strategy

A total synthesis\nof (−)-aspidospermidine via an enantioselective\nPd-catalyzed allylic substitution strategy is reported. This represents\nthe first application of a Pd-catalyzed allylic substitution with\na 3-substituted indole derivative in the synthesis of <i>Aspidosperma</i> alkaloids. In our synthetic route, the allylic substitution reaction\nwas the stereo defining step. The pentacyclic framework was then constructed\nin a fully diastereoselective sequence. This culminated in the shortest\nenantioselective synthesis of aspidospermidine reported to date, in\nseven linear steps.