Abstract: Kinetic and'* O-labeling studies demonstrate that in the hydrolysis of nonenolizable acetoacetate esters, the carbonyl hydrate acts as a nucleophilic catalyst. A cyclic four- membered lactone is formed and later opens. Structure/reactivity studies showed the rate- determining step to be a function of the pK, of the leaving group and the substituent bound to C, of the acetoacetate residue. Rate accelerations of 4 to IO4 were observed for ...
