KINETICS OF THE ACETATE ION CATALYZED KETONIZATION OF 1,3-CYCLOHEXADIENOL - EQUILIBRIUM-CONSTANTS FOR THE ENOLIZATION OF 2-CYCLOHEXENONE AND 3-CYCLOHEXENONE
KINETICS OF THE ACETATE ION CATALYZED KETONIZATION OF 1,3-CYCLOHEXADIENOL - EQUILIBRIUM-CONSTANTS FOR THE ENOLIZATION OF 2-CYCLOHEXENONE AND 3-CYCLOHEXENONE
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DOI：
10.1021/jo00290a038
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发表时间：
1990-02-02
影响因子：
3.6
通讯作者：
POLLACK, RM
中科院分区：
文献类型：
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作者：
DZINGELESKI, GD;BLOTNY, G;POLLACK, RM
通过酸性磷酸酶催化 1, 3-环己二烯基磷酸酯的水解，在水溶液中生成了共轭烯醇 1, 3-环己二烯醇 (2)。 In acetate buffers (pH 4.2—5.1), 2 ketonizes almost exclusively to the unconjugated ketone 3-cyclohexenone (1), rather than the conjugated ketone 2-cyclohexenone (3).利用乙酸盐催化的 2 酮化反应 (k0kc= 16.3±1.5 M" 1 s'1) 和乙酸盐离子催化 1 的 C-2 氢氘交换 (feei0Ac=(9.3±1.5) X 10'5 M" 1 s" 1) 的速率常数，以及一般碱催化的外推文献数据isomerizationof 1-* 3，计算 1-» 3 异构化的所有微观速率常数。这些速率常数提供 3-环己烯酮 (pKE= 5.3) 和 2-环己烯酮 (pifE= 7.7) 的酮-烯醇平衡常数值。
The conjugated enol 1, 3-cyclohexadienol (2) has been generated in aqueous solution by the acid phosphatase catalyzed hydrolysisof 1, 3-cyclohexadienyl phosphate. In acetate buffers (pH 4.2—5.1), 2 ketonizes almost exclusively to the unconjugated ketone 3-cyclohexenone (1), rather than the conjugated ketone 2-cyclohexenone (3). The rate constants for acetate-catalyzed ketonization of 2 (k0kc= 16.3±1.5 M" 1 s'1) and for acetate ion catalyzed deuterium exchange of the C-2 hydrogen of 1 (feei0Ac=(9.3±1.5) X 10'5 M" 1 s" 1) were utilized, along with extrapolated literature data on the general base catalyzed isomerizationof 1-* 3, to calculate all of the microscopic rate constants for the isomerization of 1-» 3. These rate constants provide values for the keto-enol equilibrium constants for 3-cyclohexenone (pKE= 5.3) and 2-cyclohexenone (pifE= 7.7).