Structural effects on the rates of formation and the stability of enols of cyclic benzyl ketones
作者:Sherif Eldin、Ralph M. Pollack、Dale L. Whalen
DOI:10.1021/ja00004a041
日期:1991.2
The acid dissociation constants (KaK), the keto-enol equilibrium constants (K& and the rate constants for enolization of the cyclic benzyl ketones 2-indanone (la), 2-tetralone (3,4-dihydro-2( 1H)-naphthalenone, lb) and 2-benzosuberone (3,4- benzo-3-cyclohepten-I-one, IC) were measured in aqueous solution at 25 "C. The rate constants for ketonization of the enols and the acid dissociation constants
pKaK 值为 12.2 (la)、12.9 (lb) 和 14.9 (IC)。类似地,烯醇的酸解离常数随着环尺寸的增加而降低;pKaE 为 8.3 (Za)、9.2 (2b) 和 10.0 (2c)。烯醇化的平衡常数也随环大小而变化;pKE 值为 3.8 (la)、3.6 (lb) 和 4.9 (IC)。