Aldol Condensation <i>Versus</i> Superbase-Catalyzed Addition of Ketones to Acetylenes: A Quantum-Chemical and Experimental Study
作者:Vladimir B. Orel、Nadezhda M. Vitkovskaya、Alexander S. Bobkov、Nadezhda V. Semenova、Elena Yu. Schmidt、Boris A. Trofimov
DOI:10.1021/acs.joc.1c00388
日期:2021.6.4
the interaction of two, three, or four molecules of ketone, resulting in the formation of linear products of the condensation. The formation of the condensation products with the isophorone skeleton can significantly hinder the cascade reactions of ketones with acetylenes [to afford 6,8-dioxabicyclo(3.2.1)octanes or acylcyclopentenols] promoted by superbases. In particular, the kinetically more preferable
已使用 B2PLYP(D2)/6-311+G**//B3LYP/6-31+G* 量子化学方法研究了酮在 KOH/DMSO 超碱性介质中羟醛缩合的机理。发现三个酮分子的相互作用导致形成环己-2-烯酮结构[异佛尔酮或3,5-二环己基-5-甲基螺(5.5)undec-2-en-1-one]在热力学上更比两个、三个或四个酮分子的相互作用更有利,导致形成线性缩合产物。与异佛尔酮骨架的缩合产物的形成可以显着阻碍由超碱促进的酮与乙炔的级联反应 [得到 6,8-二氧杂双环 (3.2.1) 辛烷或酰基环戊烯醇]。特别是,2-甲基-3-丁炔-2-醇的自乙烯基化和丙酮的自缩合在动力学上更优选的反应是丙酮与乙炔相互作用不会导致级联组件产物的原因。实验证实了这些副反应产物的主要形成。