Stereoselective Synthesis of the C(1)−C(12) Fragments of Tedanolides − Application of a syn-Selective Tin(II)-Mediated Aldol Reaction and a Convertible Methoxybenzyl Protecting Group
作者:Katsuya Matsui、Bao-Zhong Zheng、Shin-ichi Kusaka、Masaya Kuroda、Katsuya Yoshimoto、Haruo Yamada、Osamu Yonemitsu
DOI:10.1002/1099-0690(200110)2001:19<3615::aid-ejoc3615>3.0.co;2-p
日期:2001.10
Stereoselective synthesis of two C(1)−C(12) fragments, 3 and 4, of antitumor agents tedanolide (1) and 13-deoxytedanolide (2) was achieved by means of several regio- and/or stereoselective reactions. Ethyl ketone 14 was synthesized from methyl (S)-3-hydroxy-2-methylpropionate (16a) by way of a Weinreb amide. A highly syn-selective tin(II)-mediated aldol reaction between 14 and aldehyde 15, prepared
通过几种区域和/或立体选择性反应实现了两种 C(1)-C(12) 片段 3 和 4 的立体选择性合成,即抗肿瘤剂 tedanolide (1) 和 13-deoxytedanolide (2)。乙基酮 14 由 (S)-3-羟基-2-甲基丙酸甲酯 (16a) 通过 Weinreb 酰胺合成。由 (R)-丙酸酯 16b 制备的 14 和醛 15 之间的高度顺选择性锡 (II) 介导的羟醛反应顺利进行,随后还原得到二醇 13,将其转化为 3,并包含 C(3) ,C(5)-MP 缩醛部分,利用可转换的 MPM 保护基团。还合成了另一个具有 C(3)-O-甲基和 C(5)-O-MPM 基团的片段 4。一个关键步骤是将 C(2),C(3)-二醇 21 选择性转化为 C(2)-O-TBS、C(3)-O-Me 化合物 22。