作者:Christian Herb、Alexander Bayer、Martin E. Maier
DOI:10.1002/chem.200400617
日期:2004.11.19
was used, after hydroboration, for a Suzuki cross-coupling reaction with vinyl iodide 15. The derived seco acid 18 was converted into the macrolactone 19 by a Mitsunobu lactonization by using immobilized triphenylphosphine. Alternatively, an aldol reaction of 8 with the 4-pentenoyl derivative 20 was used to prepare alkene 26. This building block led to ester 28, which could also be converted into macrolactone
本文说明了在C-15处含有3-(对甲氧基苄氧基)丙基侧链的大内酯19的两种有效途径。通过Noyori还原酮酯5在C-15上引入手性中心。从酮酯5制备两种途径共有的中间体醛8。随后的扩链利用了Evans aldol反应。第一种途径产生烯烃14,其在硼氢化后用于与碘代乙烯15的Suzuki交叉偶联反应。通过使用固定的三苯基膦通过Mitsunobu内酯化,将衍生的癸二酸18转化为大内酯19。或者,使用8与4-戊烯酰基衍生物20的醛醇缩合反应来制备烯烃26。该结构单元导致酯28,其也可以通过经典的闭环复分解反应转化为大内酯19。在C-15侧链转化为相应的醛后,通过血红素形成和形式上的水消除来引入烯酰胺。双键异构体的分离和甲硅烷基保护基的去除提供了水杨基卤代酰胺A(E)-1和B(Z)-1。