Enols derived from malonic acids as intermediates in nitrosation and halogenation
作者:D.Lyn H. Williams、Alan Graham
DOI:10.1016/s0040-4020(01)80471-3
日期:1992.1
We propose minimum figures of 1.0 × 10−8 and 1.6 × 10−8 respectively for KE the enolisation equilibrium constant for malonic acid and methylmalonic acid. The kinetic term second order in [malonic acid] or its derivatives (when enolisation is rate limiting) has been shown to arise from a base catalysed component to the reaction brought about by the malonate ion, which dominates at pH values greater than
丙二酸,甲基丙二酸,乙基丙二酸和苯基丙二酸通过其相应的烯醇或烯醇化物形式与亲电子亚硝化剂以及与溴和碘反应。在大多数情况下,它可以使任一enolisation或烯醇限速由反应物浓度和反应性的适当选择的反应。烯醇化速率常数与存在的文献值相当吻合。我们建议K E的最小数字分别为1.0×10 -8和1.6×10 -8丙二酸和甲基丙二酸的烯醇化平衡常数。已显示[丙二酸]或其衍生物中的动力学术语二阶(当烯醇化是限速时)是由丙二酸根离子引起的碱催化组分引起的反应引起的,该丙二酸根离子在pH值大于ca时起主导作用。3。