Energy of Activation for the Acid-catalysed Hydrolysis of Esters

ACTIVATION energies of the order of 30 kcal./mol. have been found for the acid-catalysed hydrolysis of tert. -butyl 2 : 4 : 6 trimethylbenzoate and tert. -butyl benzoate, for which the reaction has been shown to proceed by alkyl–oxygen fission 1 , and of tert. -amyl 2 : 4 : 6 trimethylbenzoate, tert. -amyl benzoate, diphenylmethyl 2 : 4 : 6-trimethylbenzoate and α-methylallyl 2 : 4 : 6-trimethylbenzoate, where the same mode of fission may be predicted. This value is significantly higher than that found for the hydrolysis of esters by acyl–oxygen fission, and seems to be characteristic of this mechanism.