Tetrahedral intermediates 4. The effect of chloro-substituents on the kinetics of the breakdown of hemiorthoesters
作者:Brian Capon、Miranda I. Dosunmu
DOI:10.1016/s0040-4020(01)88793-7
日期:1984.1
1-Hydroxy-2-chloromethyl-1,3-dioxolane (4) and 1-hydroxy-2-dichloromethyl-1, 3-dioxolane (5) have been detected as intermediates by1H NMR spectroscopy in the hydration of respectively 2-chloromethylene-1, 3-dioxolane and 2-dichloromethylene-1, 3-dioxolane in aqueous acetonitrile. The kinetics of the breakdown of (4) and (5) into ethylene glycol monochloroacetate and monodichloroacetate have been studied by uv spectroscopy
通过1 H NMR光谱分别检测到1-羟基-2-氯甲基-1,3-二氧戊环(4)和1-羟基-2-二氯甲基-1,3-二氧戊环(5)的中间体乙腈水溶液中的氯亚甲基-1,3-二氧戊环和2-二氯亚甲基-1,3-二氧戊环。通过紫外光谱研究了将(4)和(5)分解为乙二醇单氯乙酸酯和单二氯乙酸酯的动力学,并评估了k H +,k HO-和k H 2 O的值。结果发现,引入chlorosubstituents成2-羟基-2-甲基-1,3-二氧戊环引起的降低ķ ħ +中和增加ķ ħ2 O - k H 2 O的分解几乎没有变化。讨论了这些反应的机理。当下