Enantiospecific Total Synthesis of (−)-Anhydromacrosalhine-methine and Partial Synthesis of the Antiamoebic Bisindole Alkaloid (−)-Macrocarpamine<sup>1</sup>
作者:Tong Gan、James M. Cook
DOI:10.1021/jo971570t
日期:1998.3.1
An enantiospecific total synthesis of (-)-anhydromacrosalhine-methine (7a) was completed from D-(+)-tryptophan via the asymmetric Pictet-Spengler reaction. In addition, a partial synthesis of (-)-anhydromacrosalhine-methine (7a) was carried out from the natural product (+)-ajmaline (10). The coupling reaction of plant-derived (+)-pleiocarpamine (8) with synthetic diene 7a provided the antiamoebic bisindole alkaloid (-)-macrocarpamine (1) in 75% yield. This sequence serves as the first example of the action of a nucleophile at [at C(2)] on a protonated form [C(3)] of pleiocarpamine 8 in the Alstonia series to provide a bisindole alkaloid.
Alkaloids from the stem-bark of Alstonia macrophylla
作者:Toh-Seok Kam、Ing-Ho Iek、Yeun-Mun Choo
DOI:10.1016/s0031-9422(99)00044-8
日期:1999.7
Three new indole alkaloids, viz. 10-methoxyaffinisine, 10-methoxycathafoline and alstonerinal, in addition to alstonerine, alstonisine, alstonal, alstophylline, vincamajine, lochnerine and cathafoline were isolated from the stem-bark extract of Alstonia macrophylla. (C) 1999 Elsevier Science Ltd. All rights reserved.