Giorgio Cevasco and Sergio Thea
The hydrolysis of aryl esters of 3,5-dimethyl-4-hydroxybenzenesulfonic acid in moderately to strongly alkaline aqueous solution follows a dissociative pathway with the participation of a sulfoquinone (thioquinone dioxide) intermediate. Brønsted-type correlation between log kapp and pKLG and inspection of the effective charge changes involved in the reaction further support the ElcB mechanism. From this and previous studies it appears that aryl esters of hydroxyarenesulfonic acids seem to be more inclined to hydrolyse through dissociative pathways than the corresponding hydroxyarenecarboxylic acids esters.