Imidazole has been found to be a catalyst for the hydrolysis of alkyl acetyl esters (CH3COOR') in which the pKa of HOR' is less than pKw. The catalytic coefficient for imidazole catalysis in these cases has been found to be associated with a deuterium solvent kinetic isotope effect (i.e., RH/kD) of 2 to 4. It is suggested that the mechanism represents an imidazole general base or general acid-catalyzed hydrolysis. The rate of alkaline hydrolysis of the cyclopentyl ester of dichloroacetic acid has been shown to be only about half as sensitive to facilitation by a neighboring hydroxyl group as previously found for the corresponding acetyl ester. In addition, the rate of imidazole general base-catalyzed hydrolysis of cyclopentyl dichloroacetate has been found to be completely insensitive to the presence of a neighboring hydroxyl group.
All Science Journal Classification (ASJC) codes
- Colloid and Surface Chemistry