Cycloaddition Protocol for the Assembly of the Hexacyclic Framework Associated with the Kopsifoline Alkaloids

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• 作者：Xuechuan Hong ; Stefan France ; José ; M. Mejí ; a-Oneto ; Albert Padwa
• 刊名：Organic Letters
• 出版年：2006
• 出版时间：October 26, 2006
• 年：2006
• 卷：8
• 期：22
• 页码：5141 - 5144
• 全文大小：97K
• 年卷期：v.8,no.22(October 26, 2006)
• ISSN：1523-7052

文摘

An approach to the hexacyclic framework of the kopsifoline alkaloids has been developed and is based on a Rh(II)-catalyzed cyclization-cycloaddition cascade. The resulting [3+2]-cycloadduct was readily converted into the TBS enol ether 23. Oxidation of the primary alcoholpresent in 23 followed by reaction with CsF afforded compound 24 that contains the complete hexacyclic skeleton of the kopsifolines.