Journal of the American Chemical Society p. 3977 - 3980 (1989)
Update date:2022-08-11
Topics:
Chiang, Y.
Kresge, A. J.
Schepp, N. P.
Rates of hydrogen ion catalyzed enolization of acetone and ketonization of acetone enol were measured over a range of temperatures in water and in acetonitrile solution.The data give ΔH(excit.) = 20.0 +/- 0.1 kcal mol-1, ΔS(excit.) = -12.1 +/- 0.3 cal K-1 mol-1, and ΔH(excit.) = 20.1 +/- 0.5 kcal mol-1, ΔS(excit.) = -5.8 +/- 1.7 cal K-1 mol-1, for enolization in water and acetonitrile, respectively, and ΔH(excit.) = 9.7 +/- 0.4 kcal mol-1, ΔS(excit.) = -8.6 +/- 1.4 cal K-1 mol-1, and ΔH(excit.) = 11.4 +/- 0.2 kcal mol-1, Σ(excit.) = 1.6 +/-0.8 cal K-1 mol-1, for ketonization in water and acetonitrile, respectively.These values lead to ΔH0 = 10.3 +/- 0.4 kcal mol-1, ΔS0 = -3.5 +/- 1.5 cal K-1 mol-1, for the keto-enol equilibrium in water, and ΔH0 = 8.7 +/- 0.6 kcal mol-1, ΔS0 = -7.4 +/- 1.9 cal K-1 mol-1, for the equilibrium in acetonitrile.This is the first determination of thermodynamic parameters for a simple ketone-enol equilibrium in solution; the results are remarkably similar to the thermodynamic parameters for this reaction in the gas phase.A mechanism involving acid catalysis of the bromination of acetone enol by N-bromosuccinimide, the process used to monitor enolization in acetonitrile solution, is ruled out.
View MoreTianjin Realet Chemical Technology Co.,Ltd.
website:http://www.realetchem.com
Contact:+86-022-58788819
Address:shuanggang industrial park
Contact:+86-21-61318535
Address:Building 29,No.2139 Xizha Road, Fengxian District, Shanghai
Nanjing distinctions Medical Technology Co., Ltd.
Contact:+86-15996203785 13914714059
Address:nanjing,jiangsu , China
Shanghai agrotree chemical co.,ltd.
Contact:+86-21-50117563
Address:Room 8A,liangfeng building,No.8 dongfang RD.pudong,shanghai,China
Contact:86-512-87182056
Address:No.128 Fangzhou Rd, Suzhou Industrial Park, China, 215125, China
Doi:10.1021/j100126a017
(1993)Doi:10.1016/S0031-9422(00)97687-8
(1983)Doi:10.1021/jo0352934
(2003)Doi:10.1002/hlca.201500026
(2015)Doi:10.1016/j.tetlet.2014.08.087
(2014)Doi:10.1016/j.tetlet.2016.10.107
(2016)