question_answer

Which of the following carboxylic acids undergoes decarboxylation easily?

A) \[{{C}_{6}}{{H}_{5}}-CO-C{{H}_{2}}-COOH\]                      

B) \[{{C}_{6}}{{H}_{5}}-CO-COOH\]

C)  \[{{C}_{6}}{{H}_{5}}-\underset{\begin{smallmatrix}  | \\  OH \end{smallmatrix}}{\mathop{CH}}\,-COOH\]

D)  \[{{C}_{6}}{{H}_{5}}-\underset{\begin{smallmatrix}  | \\  N{{H}_{2}} \end{smallmatrix}}{\mathop{CH}}\,-COOH\]

Correct Answer: A

Solution :

The \[\beta \]-keto acids on heating easily undergo decarboxylation via a six membered cyclic transition state.