REMOVAL OF THE ACTIVATING CARBETHOXY GROUP
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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.