High stereoselectivity in the Wittig reaction induced by the interaction of charges
作者:Ulrich Klar、Peter Deicke
DOI:10.1016/0040-4039(96)00780-0
日期:1996.6
The synthesis of carbacyclin analogues I based on the introduction of an α-chain to a suitable substituted bicyclo[3.3.0]octan-3-one derivative like 5 by a Wittig reaction leads generally to nearly 1:1-mixtures of E/Z-isomers. This lack of selectivity will change dramatically, if an acidic sulfonamide in the bicyclic framework is present. The observed Z-selectivity can be explained by an interaction
基于通过Wittig反应将α链引入合适的取代双环[3.3.0] octan-3-one衍生物(如5)的碳环素类似物I的合成通常会导致E / Z接近1:1的混合物-异构体。如果在双环骨架中存在酸性磺酰胺,则选择性的缺乏将发生巨大变化。观察到的Z选择性可以用Wittig试剂中去质子化的磺酰胺和亲电性磷原子的电荷相互作用来解释。