Iterative Synthesis of Deoxypropionate Units: The Inductor Effect in Acyclic Conformation Design
作者:Stephen Hanessian、Navjot Chahal、Simon Giroux
DOI:10.1021/jo061098o
日期:2006.9.1
Conjugate addition of lithium dimethylcuprate to acyclic α,β-unsaturated esters of varying lengths bearing terminal alkyl or phenyl groups leads to a preponderance of syn 1,3-adducts when one methyl is already present. Conversion to enoates, and iteration of cuprate additions also favors syn adducts to give contiguous deoxypropionate units in a growing chain. The effect of end-group variation (Me,
当已经存在一个甲基时,将二甲基铜酸锂共轭加成至具有末端烷基或苯基的可变长度的无环α,β-不饱和酯会导致大量的1,3-加合物。转化为烯酸酯,以及反复添加铜酸盐也有利于合成加合物,以在增长的链中提供连续的脱氧丙酸酯单元。端基变化(Me,i- Pr,苯基,叔丁基)与酯基(Me,叔-丁基等)对顺式和反式产物的非对映选择性进行了研究。根据在电感上有利的折叠构象中与1,5-戊烷相互作用的最小化相关的感应效应,这些结果是合理的,并且通过均解偶联NMR研究得到了证实。