Evolution of an oxidative dearomatization enabled total synthesis of vinigrol.
Evolution of an oxidative dearomatization enabled total synthesis of vinigrol.
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DOI：
10.1039/c3ob42191k
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发表时间：
2014-01-14
影响因子：
3.2
通讯作者：
Das P
中科院分区：
文献类型：
--
作者：
Yang Q;Draghici C;Njardarson JT;Li F;Smith BR;Das P
介绍了导致维尼醇全合成的合成策略的演变。氧化脱芳构化/分子内第尔斯-阿尔德环加成已成为所有方法的成功基石。形成四环核心的广泛的自由基环化努力产生了有趣且令人惊讶的反应结果，其中没有一个可以推进到维尼醇。通过使用 Heck 代替激进环化，成功克服了这些环化障碍。全合成的特点是首次在有机合成中使用三氟乙醚保护基团。介绍了其选择的逻辑以及该基团在保护 C8a 羟基之外的重要性，并讨论了其去除策略。由于紧凑的四环笼，该路线是围绕许多不寻常的反应观察而建立的，并且已经出现了解决方案。例如，首次发现了以三氟乙基离去基团为特征的 Grob 裂解反应，观察到有趣的间断二氧化硒烯丙基氧化以及有趣的催化剂和抗衡离子依赖性定向氢化。
The evolution of the synthetic strategy resulting in a total synthesis of vinigrol is presented. Oxidative dearomatization/intramolecular Diels-Alder cycloaddition has served as the successful cornerstone for all of the approaches. Extensive radical cyclization efforts to form the tetracyclic core resulted in interesting and surprising reaction outcomes, none of which could be advanced to vinigrol. These cyclization obstacles were successfully overcome by using Heck instead of radical cyclizations. The total synthesis features a trifluoroethyl ether protecting group being used for the first time in organic synthesis. The logic of its selection and the group’s importance beyond protecting the C8a hydroxyl group is presented along with a discussion of strategies for its removal. Because of the compact tetracyclic cage the route is built around many unusual reaction observations and solutions have emerged. For example, a first of its kind Grob fragmentation reaction featuring a trifluoroethyl leaving group has been uncovered, interesting interrupted selenium dioxide allylic oxidations have been observed as well as intriguing catalyst and counterion dependent directed hydrogenations.
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影响因子：
2.3
作者：
DUBOUDIN, JG;JOUSSEAUME, B
通讯作者：
JOUSSEAUME, B
影响因子：
3.6
作者：
BRAISH, TF;SADDLER, JC;FUCHS, PL
通讯作者：
FUCHS, PL
影响因子：
15
作者：
Abdo, Mohannad;Knapp, Spencer
通讯作者：
Knapp, Spencer
影响因子：
3.6
作者：
Brennan, NK;Guo, X;Paquette, LA
通讯作者：
Paquette, LA
影响因子：
3.3
作者：
ANDO, T;TSURUMI, Y;OKUHARA, M
通讯作者：
OKUHARA, M