Applications of Vinylogous Mannich Reactions. Concise Enantiospecific Total Syntheses of (+)-Croomine
作者:Stephen F. Martin、Kenneth J. Barr、Dudley W. Smith、Scott K. Bur
DOI:10.1021/ja990077r
日期:1999.8.1
extraordinarily concise asymmetric syntheses of (+)-croomine (1) have been completed using a novel strategy, highlighted by two vinylogous Mannich reactions as key constructions. The first such reaction involved the addition of 5-(4-bromobut-1-yl)-3-methyl-2-(triisopropylsilyloxy)furan to the N-acyliminium salt derived from the l-pyroglutamic acid derivative 17 to give the adduct [5(S),2‘(S),5‘(S)]-5-(4‘