General approach for the synthesis of ajmaline/sarpagine indole alkaloids: Enantiospecific total synthesis of (+)-ajmaline, alkaloid G, and norsuaveoline via the asymmetric Pictet-Spengler reaction
A general approach (oxyanion-Cope strategy) for the synthesis of sarpagine/ajmaline indole alkaloids has been developed. (+)-Ajmaline 1 and alkaloid G 2 as well as norsuaveoline 3 have been synthesized from D-(+)-tryptophan in enantiospecific fashion via