yields up to 80%. The diastereoisomer ratio varied from 2 : 1 to 29 : 1 for 11mb, and from 2 : 1 to 46 : 1 (syn/anti) for 12mb, depending on reaction conditions, as shown by X-ray crystallographic analysis of 14mb. The relationship between the size of the alkyl groups on the chlorosilane reagent (Me2R″SiCl, R″=Cl, Me, t-Bu, Ph) used as an enolate trap and the observed stereoselectivity was investigated
N-保护的,甲
硅烷基化的烯丙基甘
氨酸盐11和12的克莱森重排导致形成高达80%的产率的烯丙基/甲
硅烷基官能化的
氨基酸13和14。根据14mb的X射线晶体学分析,取决于反应条件,非对映异构体的比率为11mb,从2:1到29:1 ,从12mb,从2:1到46:1(顺/反)变化。
氯硅烷试剂(Me 2 R” SiCl,R” = Cl,Me,t-Bu,Ph)用作烯醇化物陷阱,并在爱尔兰-克莱森(Claisen)变体的情况下研究了观察到的立体选择性。Me 3 SiCl给出了最佳结果。然而,甲
硅烷基化的酯上的烷基的大小(Me 2 R''Si,R = Me,t -Bu,Ph,i-Pr)对非对映选择性或重排产率没有显着影响。