Total Synthesis of (.+-.)-Dragmacidin: A Cytotoxic Bis(indole)alkaloid of Marine Origin
作者:Biao Jiang、Joanne M. Smallheer、Carol Amaral-Ly、Mark A. Wuonola
DOI:10.1021/jo00101a051
日期:1994.11
The total synthesis of the cytotoxic marine alkaloid, (+/-)-dragmacidin, trans-6,7-dibromo-3-[5-(6-bromo-1H-indol-3-yl)-4-methyl-2-piperazinyl]-1H-indol-4-ol, is described. The synthesis proceeds through the condensation of (6-bromoindol-3-yl)-alpha-(methylamino)acetonitrile with (6,7-dibromo-4-methoxyindol-3-yl)-alpha-oxoacetyl chloride. The product of this condensation was converted in two steps to an intermediate containing the central diketopiperazine ring which after reduction and deprotection gave the racemic natural product along with its cis isomer. An efficient preparation of 6,7-dibromo-4-methoxyindole is also presented.