Kinetic studies of ester hydrolysis

Kinetic studies of ester hydrolysis in strongly acidic solutions were carried out by Yates (110). A modified Bunnett equation (eq. 81) was used with r replacing w, and m with a value of 0.62 to correct the Ho scale for ester protonation. The rate dependence of various acetate esters on sulfuric acid concentration was found to fit into four basic classes. Type I is characterized by an initial steady rate increase with acid concentration passing through a maximum, followed by a decrease, then a modest increase (Fig. 7). This behavior is typical of primary alkyl acetates. Type II behavior is very similar, except that the rate maximum is observed at much lower obs values, and the final rate increase is much sharper and starts at much lower H2SO4 concentrations. This is characteristic of secondary alkyl, benzyl, and allyl acetates. Type III shows a steady rate increase with increasing... 

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