Convergent total synthesis of (.+-.)-colchicine and (.+-.)-desacetamidoisocolchicine
作者:D. A. Evans、S. P. Tanis、D. J. Hart
DOI:10.1021/ja00409a032
日期:1981.9
Total syntheses of (&)-desacetamidoisoolchicine (2b) and (&)-colchicine (la) have been achieved. Key features of the synthetic sequence are the facile incorporation of a tropolone dication equivalent via ketone 6 and introduction of the 7-acetamido group. Some of the mechanistic details of the conversion of alcohol 7 to dihydrotropolone 8 and alcohols 14a,b to ester 19 are discussed. Colchicine (la)
(&)-去乙酰氨基异秋水仙碱(2b)和(&)-秋水仙碱(la)的全合成已经实现。合成序列的关键特征是通过酮 6 和 7-乙酰氨基基团的引入轻松掺入托酚酮双阳离子等价物。讨论了醇 7 转化为二氢托酚酮 8 和醇 14a、b 转化为酯 19 的一些机制细节。秋水仙碱 (la),一种主要的生物碱成分