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)