Chelation controlled aldol additions of the enolsilane derived from tert-butyl thioacetate : a stereosetective approach to 1β-methylthienamycin
作者:Cesare Gennari、Pier Giorgio Cozzi
DOI:10.1016/s0040-4020(01)81455-1
日期:1988.1
The tert-butyldimethylenolsilane derived from tert-butyl thioacetate is a useful reagent for highly stereoselective chelation-controlled additions to chiral α-alkoxy and α-methyl-β-alkoxy aldehydes where the corresponding acetate fails. The aldol product deriving from the TiCl4 mediated addition to α-methyl-β-alkoxy aldehyde 5 was elaborated In high yield to give the bicyclic β-lactam 11, an Intermediate
衍生自硫代乙酸叔丁酯的叔丁基二甲基烯醇硅烷是用于手性α-烷氧基和α-甲基-β-烷氧基醛类(其中相应的乙酸酯失效)的高度立体选择性螯合控制加成的有用试剂。高产率地制备了由TiCl 4介导的加成至α-甲基-β-烷氧基醛5的醛醇产物,得到双环β-内酰胺11,其为制备1β-甲基噻吩霉素的中间体。TiCl 4介导的缩合过程中与醛5的部分消旋化有关的问题尚未完全解决。