The acid-catalyzed hydrolysis of methyl acetate, ( CH_3COOCH_3 )
CHEMISTRY · Multi-part · A Level · Chemistry · Introduction to organic chemistry · Introduction to organic chemistry
Problem
The acid-catalyzed hydrolysis of methyl acetate, CH3COOCH3, in aqueous solution proceeds much faster in 0.10 M HCl than in neutral water at the same temperature.
(a) Construct a plausible sequence of elementary steps for the hydrolysis mechanism in the presence of a generic acid catalyst H+. Clearly indicate all charged intermediates and the step in which the catalyst is regenerated.
(b) Identify the rate-determining step of your mechanism and justify your choice based on bond-breaking/forming considerations.
(c) Predict how the observed rate would change if the reaction were carried out in heavy-water D2O with D3O+ as the catalyst instead of H3O+. Provide a mechanistic explanation for your prediction that references isotope effects.
(d) Suppose the carbonyl oxygen is labeled with 18O. Explain where the 18O isotope would be found in the products according to your mechanism and how this observation supports the pathway you proposed.