Base catalysis as an alternative explanation for an apparent deuterium solvent isotope effect in the photochemical reactions of α,β-unsaturated esters
作者:Alan C. Weedon
DOI:10.1139/v84-332
日期:1984.10.1
conclusion is used to explain the apparently anomalous photochemistry of esters 1 and 5 in non-deuterated solvents. The results described also exemplify the use of a base to enhance the efficiency and to alter the direction of deconjugation in the photochemical conversion of α,β-unsaturated esters to their β,γ-unsaturated isomers.
对 α,β-不饱和酯 3,4,4-三甲基-2-戊烯酸乙酯 1 和 3,4-二甲基-2-戊烯酸乙酯 4 的光化学反应的明显氘溶剂同位素效应是重新审查;得出的结论是,反应速率的变化可归因于所用溶剂中存在的碱性杂质对反应中间体(光化学产生的二烯醇)的拦截。该结论用于解释酯 1 和 5 在非氘化溶剂中明显异常的光化学。所描述的结果还举例说明了使用碱来提高效率并改变 α,β-不饱和酯到其 β,γ-不饱和异构体的光化学转化中的解偶联方向。