“<i>Syn-Effect</i>” in the Conversion of (<i>E</i>)-α,β-Unsaturated Esters to the Corresponding β,γ-Unsaturated Esters
作者:Samar Kumar Guha、Atsushi Shibayama、Daisuke Abe、Yutaka Ukaji、Katsuhiko Inomata
DOI:10.1246/cl.2003.778
日期:2003.8
The stereochemistry in the conversion of (E)-α,β-unsaturated esters to the corresponding β,γ-unsaturated esters by treatment with lithium hexamethyldisilazide in the presence of HMPA was investigated. The Z/E ratios of the resulting β,γ-unsaturated esters varied according to the γ-substituents of the (E)-α,β-unsaturated esters. This phenomenon was rationalized by “syn-effect” which may be attributed
研究了在 HMPA 存在下用六甲基二硅叠氮化锂处理将 (E)-α,β-不饱和酯转化为相应的 β,γ-不饱和酯的立体化学。所得β,γ-不饱和酯的Z/E比率根据(E)-α,β-不饱和酯的γ-取代基而变化。这种现象被“合成效应”合理化,这可能主要归因于 σ→π* 相互作用和/或 6π-电子同芳香性。