REMOVAL OF THE ACTIVATING CARBETHOXY GROUP
q The ester function is first hydrolyzed under alkaline conditions, i.e., base promoted ester hydrolysis. Recall that this gives the carboxylate salt in the last step.
q Then the carboxylate salt is acidified to generate the carboxylic acid.
q Finally the ketoacid is warmed to expel carbon dioxide and generate the enol form of the ketone, which then rapidly ketonizes.