Lemieux René M., Devine Paul N., Mechelke Mark F., Meyers A. I.
Department of Chemistry, Colorado State University, Fort Collins, Colorado 80523.
J Org Chem. 1999 May 14;64(10):3585-3591. doi: 10.1021/jo982426q.
Sequential allylation of chiral, nonracemic thiolactam 8 affords clean thio-Claisen [3,3] products 11. The stereoselectivity of the rearrangement was found to be on the order of 10-11:1, with the exo-endo products responsible for the mixture. Addition of hydride or methyllithium-cerium chloride gave clean addition to the thiolactam in the form of its iminium salts 12. Hydrolysis gave 4,4-dialkylcyclohexenones 15, which were cyclized to the cyclopentene derivatives 16 using Grubbs' catalyst.
手性非外消旋硫代内酰胺8的顺序烯丙基化反应可得到纯净的硫代克莱森[3,3]产物11。发现重排反应的立体选择性约为10 - 11:1，外-内型产物导致了混合物的形成。加入氢化物或甲基锂-氯化铈能以亚胺盐12的形式实现对硫代内酰胺的纯净加成。水解反应得到4,4-二烷基环己烯酮15，使用格拉布催化剂将其环化生成环戊烯衍生物16。
