Total Synthesis of (+)-HapIophytine

摘要

Haplophytine (1) is the major indole alkaloid found in the dried leaves of the Mexican plant Haplophyton cimicidum and was first isolated by Snyder and co-workers in 1952. Two decades after its isolation, Yates, Cava, and co-workers determined its structure by X-ray crystallography. Haplophytine (1) is composed of two segments that are connected by the formation of a quaternary carbon center (Scheme 1). The left-half segment has an exceptionally unique structure, which possesses a bicyclo[3.3.1]skeleton that includes bridged ketone and aminal functionalities. The right-half segment is a hexacyclic aspidosperma class of alkaloid, named aspidophy-tine, which is obtained by the acidic degradation of (+)-haplophytine.