Catalyzed Asymmetric Diels−Alder Reaction of Benzoquinone. Total Synthesis of (−)-Ibogamine†
journal contributionposted on 29.06.2000, 00:00 by James D. White, Younggi Choi
The Diels−Alder addition of diene 2 with benzoquinone catalyzed by (S)-BINOL−TiCl2 produced cycloadduct 5 in >65% yield and 87% ee. The cycloadduct was transformed into (−)-ibogamine in nine steps (10% overall yield from benzoquinone). A model for the transition state leading to 5 is proposed.