期刊
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
卷 122, 期 20, 页码 4893-4903出版社
AMER CHEMICAL SOC
DOI: 10.1021/ja000234i
关键词
-
Among the most structurally remarkable guanidine natural products are the crambescidin/ptilomycalin A family of marine alkaloids. The evolution of a practical strategy for preparing pharmacologically significant crambescidin/ptilomycalin A alkaloids that lack oxidation at C13 is described. The first total syntheses of crambescidin 800 (2), crambescidin 657 (6), and neofolitispate 2 (7) are reported in full detail. The central strategic step in these convergent total syntheses is tethered Biginelli condensation of beta-keto ester 24 with ureido aminal 61 to combine all carbons of the guanidine nucleus and set the pivotal C10-C13 stereorelationship. The total synthesis of crambescidin 800 (2) was accomplished in 3% overall yield from commercially available 3-butyn-1-ol by way of 16 isolated and purified intermediates. Full details of our earlier total synthesis of ptilomycalin A (1) are also presented. The total syntheses described in this disclosure confirm the stereochemical assignments of 1, 2, 6, and 7 and rigorously establish that the absolute configuration of the hydroxyspermidine side chain of crambescidin 800 (2) is S.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据