Chapter 13, Problem 48P

Interpretation Introduction

Interpretation: Reason behind the formation of acetone containing ${}^{\text{18}}\text{O}$ when enzymatic decarboxylation of acetoacetate is carried out in ${\text{H}}_{\text{2}}{}^{\text{18}}\text{O}$ has to be stated.

Concept introduction: Decarboxylation of acetoacetate is initiated by an enzyme named acetoacetate decarboxylase. Enzyme forms protonate imine with substrate acetoacetate. It loses carbondioxide in presence of a ${\text{H}}_{\text{2}}{}^{\text{18}}\text{O}$ to form an enamine. The reaction proceeds further and undergoes hydrolysis to regenerate the enzyme.