Question

Which of the following compounds decarboxylates when heated?

Short answer

On heating, carboxylic acid releases carbon dioxide gas. After releasing carbon dioxide, the remaining product should be stable.[l1]

Compound C is a $\beta$ ketone. Hence, the remaining electron can be delocalized by the keto group as shown below.

[l1]Nothing about delocalization of electrons mentioned here.

Step-by-step solution

Delocalization of electrons in (c)

On heating, carboxylic acid releases carbon dioxide gas. After releasing carbon dioxide, the remaining product should be stable.[l1]

Compound C is a $\beta$ ketone. Hence, the remaining electron can be delocalized by the keto group as shown below.

[l1]Nothing about delocalization of electrons mentioned here.

A and B do not have β carboxylic group

Compounds A and B don't decarboxylate on heating because they don't have $\beta$carboxylic group to stabilize the negative charge on the ring by the loss of carbon dioxide.