Highly Regio- and Stereoselective [3+2] Cyclopentanone Annulation Using a 3-(Alkylthio)-2-siloxyallyl Cationic Species
作者:Keiichi Masuya、Kei Domon、Keiji Tanino、Isao Kuwajima
DOI:10.1021/ja972879x
日期:1998.3.1
A new synthetic method for functionalized cyclopentanones was developed on the basis of a [3+2] cycloaddition reaction of a 1-(methylthio)-2-siloxyallyl cationic species and olefins. Allyl acetates 1a and 1b, which are the precursors of the allyl cationic species, are easily prepared in three or four steps from commercially available compounds. Under the influence of EtAlCl2 or AlCl3, 1a or 1b reacted
基于 1-(甲硫基)-2-甲硅烷氧基烯丙基阳离子物质和烯烃的 [3+2] 环加成反应,开发了一种功能化环戊酮的新合成方法。乙酸烯丙酯 1a 和 1b 是烯丙基阳离子物质的前体,可通过三到四步从市售化合物轻松制备。在 EtAlCl2 或 AlCl3 的作用下,1a 或 1b 与各种烯烃如烯醇醚、乙烯基硫化物、苯乙烯和三烷基烯烃反应,以良好的收率得到相应的环戊酮。值得注意的是,在每种情况下都主要形成空间位阻更大的区域异构体。此外,1b 与乙烯基硫化物的反应表现出惊人的高立体选择性,