Intramolecular Ene Reaction of Epoxyallylsilanes: Synthesis of Allyl- and Vinylsilane-Functionalized Cyclohexanols
作者:Asunción Barbero、Pilar Castreño、Gloria Fernández、Francisco J. Pulido
DOI:10.1021/jo051868g
日期:2005.12.1
Lewis acids. Two pathways for the carbonyl ene reaction are observed: one leading to allylsilane−cyclohexanols when the epoxyallylsilane (28−31) is nonsubstituted, 2-, or 4-monosubstituted and other leading to vinylsilane−cyclohexanols when the epoxyallylsilane (24−27) is 2,4-disubstituted or trisubstituted. An explanation for the observed regio- and stereoselectivity is advanced and a reliable mechanism
带有庞大的叔丁基二苯基甲硅烷基的环氧烯丙基硅烷在用路易斯酸处理时会经历罕见的串联重排-环化过程。用于羰基烯反应两种途径中观察到:一个通向烯丙基硅烷-环己醇时epoxyallylsilane(28 - 31)是未取代的,2-,或4-单取代的和其它导致乙烯基硅烷-环己醇时epoxyallylsilane(24 - 27)是2,4-二取代或三取代。对观察到的区域选择性和立体选择性进行了解释,并提出了一种可靠的机制。