Further Studies of Intramolecular Michael Reactions of Nitrosoalkenes for Construction of Functionalized Bridged Ring Systems

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• 作者：Praveen Kumar ; Puhui Li ; Ilia Korboukh ; Tony L. Wang ; Hemant Yennawar ; Steven M. Weinreb
• 刊名：Journal of Organic Chemistry
• 出版年：2011
• 出版时间：April 1, 2011
• 年：2011
• 卷：76
• 期：7
• 页码：2094-2101
• 全文大小：941K
• 年卷期：v.76,no.7(April 1, 2011)
• ISSN：1520-6904

文摘

A wide variety of stabilized carbanions have been found to participate as nucleophiles in intramolecular Michael-type conjugate additions to in situ generated nitrosoalkenes to form bridged carbocyclic systems. The vinylnitroso platforms for these cyclizations have been prepared via two key steps involving ring-closing metathesis of vinyl chlorides and regioselective conversion of vinyl chlorides to 伪-chloroketones with sodium hypochlorite in glacial acetic acid/acetone. An alternative approach to preparation of some cyclization substrates has involved use of more reactive enol ethers as precursors to the requisite 伪-chloroketones. A sulfonamide anion has also been found to be an effective nucleophile in this type of reaction, leading to formation of a 6-azabicyclo[3.2.1]octane.