Synthesis of Epothilone 16,17-Alkyne Analogs by Replacement of the C13−C15(O)-Ring Segment of Natural Epothilone C
作者:Usama Karama、Gerhard Höfle
DOI:10.1002/ejoc.200390146
日期:2003.3
metathesis of epothilone C (4a) with ethylene, followed by silyl protection and ester hydrolysis, yielded an eastern ring segment C1−C12 as the carboxylic acid 10. Separately, a western ring segment 12 carrying a C16−C17 triple bond was synthesized and coupled with 10 to form the ester 13. Ring closure by olefin metathesis, deprotection, and then epoxidation, gave the 16,17-alkyne analogs (14b, 3b) of
埃坡霉素 C (4a) 与乙烯开环交叉复分解,然后进行甲硅烷基保护和酯水解,产生作为羧酸 10 的东部环段 C1-C12。另外,带有 C16-C17 三键的西部环段 12合成并与 10 偶联形成酯 13。通过烯烃复分解、脱保护和环氧化闭环,得到埃坡霉素 C 和埃坡霉素 A 的 16,17-炔类似物(14b, 3b)。 3b 的身份得到证实通过氢化成 (16Z)-埃坡霉素 A8 (17) 并与由天然埃坡霉素 A8 (18) 制备的真实样品进行比较。测定了新埃坡霉素的生物活性。(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)