描述了从印度尼西亚药用植物中提取的天然细胞毒性物质 (±)-eleutherol 和 eleuthoside A 的首次全合成。首先,在重氮转移化学方法的帮助下,从溴甲氧基醛开始,(±)-eleutherol 的合成分九步完成。其次,金属催化的相应重氮萘醌的分子内环化反应产生所需的刺五加酚,其作为刺五加苷 A 的前体。然后,使用不同的葡萄糖基供体对几种糖苷化途径进行了实验,以实现刺五加酚的有效 O-糖苷化。唯一成功的策略涉及在 Ag 2 O 和喹啉存在下使用全乙酰糖基溴进行 Koenigs-Knorr 糖苷化。这种策略提供了我们想要的 β-构型乙酰化糖苷,区域选择性地。最后,进行非对映异构体的脱乙酰化和连续分离,得到 eleuthoside A。
作者:Scott A. Snyder、Trevor C. Sherwood、Audrey G. Ross
DOI:10.1002/anie.201002264
日期:——
A polycyclic collapse: Use of a carefully designed acyclic intermediate participated in a cascade reaction that formed the entire core of the polyketide‐derived dalesconols in a single flask (see scheme). A number of additional and carefully controlled synthetic operations completed an expeditious synthesis of both of these highly bioactive natural products as well as structural congenors.
Synthesis and Properties of Substituted CBI Analogs of CC-1065 and the Duocarmycins Incorporating the 7-Methoxy-1,2,9,9a-tetrahydrocyclopropa[<i>c</i>]benz[<i>e</i>]indol-4-one (MCBI) Alkylation Subunit: Magnitude of Electronic Effects on the Functional Reactivity
作者:Dale L. Boger、Jeffrey A. McKie、Hui Cai、Barbara Cacciari、P. G. Baraldi
DOI:10.1021/jo952033g
日期:1996.1.1
radical-alkene cyclization (24 --> 25, 32 --> 33) for completion of the synthesis of the 1,2-dihydro-3H-benz[e]indole skeleton and final Ar-3' alkylation of 28 for introduction of the activated cyclopropane. Two approaches to the implementation of the key 5-exo-trig free radical cyclization are detailed with the former proceeding with closure of 24 to provide 25 in which the required product functionalization was