Chemical modification of a highly functionalized taxane. The consequences of an absent bridgehead double bond on oxetane D-ring construction.
Chemical modification of a highly functionalized taxane. The consequences of an absent bridgehead double bond on oxetane D-ring construction.
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高功能化紫杉烷的化学修饰。
DOI：
10.1021/jo0206566
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发表时间：
2003
期刊：
影响因子：
--
通讯作者：
Lo,HoYin
中科院分区：
文献类型：
--
作者：
Paquette,LeoA;Lo,HoYin
氧杂环丁烷 D 环已融合到高度功能化的紫杉烷2 的框架上。该合成路线基于三甲基甲硅烷基三氟甲磺酸酯促进的环氧化物开环步骤，然后是立体控制的区域反转环氧乙烷形成，以及该中间体与双(环戊二烯基)氯化钛(III)的还原转位。最后一个关键步骤提供了方便的额外羟基的实现，最终有利于分子内 SN2 反应。本文概述的路线的切向特征包括特定的重排反应和环 A 的逆羟醛裂解。
An oxetane D-ring has been fused to the framework of the highly functionalized taxane2. The synthetic route is based on a trimethylsilyl triflate-promoted epoxide-opening step, followed by stereocontrolled, regioreversed oxirane formation and reductive transposition of this intermediate with bis(cyclopentadienyl)titanium(III) chloride. This last key step provides for the convenient implementation of additional hydroxyl groups ultimately conducive to intramolecular SN2 reaction. Tangential features of the route outlined herein include specific rearrangement reactions and a retro-aldol cleavage of ring A.