A simple and novel synthetic method of 1,2,3,3a,8,8a-hexahydro-8-methoxy-1-methoxycarbonylpyrrolo[2,3-b]indoles (A), having such alkoxy group as methoxy, ethoxy, allyloxy, benzyloxy, and 2-hydroxyethoxy, at the 3a position, is developed by treating 1-methoxy-Nb-methoxycarbonyltryptamine (B) with iodine–morphorine in an appropriate alcohol as a solvent. The reaction of B with either NBS or NCS in MeOH or EtOH was also found to be another good method. In the reaction with NCS, stable 3a-chloro-1,2,3,3a,8,8a-hexahydro-8-methoxy-1-methoxycarbonylpyrrolo[2,3-b]indole (C) was formed. Treatment of C with an appropriate alcohol in the presence of silica gel produced the corresponding A. An attempt to improve the yields of A and an application of C as a building block for natural product synthesis are in progress.
