efficient method for the solvolysis of stericallyhindered esters under high pressure is described. Transesterification is carried out in the presence of DBU at room temperature and at a pressure of 10 kbar to give quantitative conversions within short reaction times. The substrates examined included aromatic and aliphatic esters of stericallyhindered alcohols and phenols. An optically pure benzyl ester
Kinetic study of hydrolysis of benzoates. Part XXIV—Variation of theortho substituent effect with solvent in the alkaline hydrolysis of substituted phenyl benzoates
The second-order rate constants k2 (M−1 s−1) for the alkaline hydrolysis of meta-, para- and ortho-substituted phenyl benzoates, C6H5CO2C6H4X, in aqueous 0.5 Mn-Bu4NBr were measured spectrophotometrically. The dependence of substituent effects, especially ortho inductive, resonance and steric terms on different solvent parameters, was studied using the following equation:
在水0.5 M n中,对间,对位和邻位取代的苯甲酸苯酯C 6 H 5 CO 2 C 6 H 4 X 进行碱水解的二级速率常数k 2(M -1 s -1)分光光度法测定-Bu 4 NBr。使用以下方程式研究了取代基效应(尤其是邻位诱导,共振和空间项)对不同溶剂参数的依赖性: