Intramolecular Diels–Alder Reactions of Cycloalkenones: Stereoselectivity, Lewis Acid Acceleration, and Halogen Substituent Effects

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• 作者：Hung V. Pham ; Robert S. Paton ; Audrey G. Ross ; Samuel J. Danishefsky ; K. N. Houk
• 刊名：Journal of the American Chemical Society
• 出版年：2014
• 出版时间：February 12, 2014
• 年：2014
• 卷：136
• 期：6
• 页码：2397-2403
• 全文大小：428K
• ISSN：1520-5126

文摘

The intramolecular Diels鈥揂lder reactions of cycloalkenones and terminal dienes occur with high endo stereoselectivity, both thermally and under Lewis-acidic conditions. Through computations, we show that steric repulsion and tether conformation govern the selectivity of the reaction, and incorporation of either BF<sub>3sub> or 伪-halogenation increases the rate of cycloaddition. With a longer tether, isomerization from a terminal diene to the more stable internal diene results in a more facile cycloaddition.