Sarpagine-related indole alkaloids (−)-hydroxygardnerine, (+)-hydroxygardnutine, (−)-gardnerine, (+)-(E)-16-epi-normacusine B, and (−)-koumine were divergently synthesized via a common intermediate possessing a piperidine ring with an exocyclic (E)-ethylidene side chain, which was constructed by a gold(I)-catalyzed 6-exo-dig cyclization strategy.
                                    sarpagine相关的
吲哚生物碱(-)-羟基gardnerine,(+)-羟基gardnutine,(-)-gardnerine,(+)-(E)-16- Epi -normacusine B和(-)-koumine是通过共同的方法合成的中间体,其具有带有环外(E)-亚乙基侧链的
哌啶环,该中间体通过
金(I)催化的6 -exo-dig环化策略构建。