What will be the product isolated after thermal decarboxylation of each of the following?...

What will be the product isolated after thermal decarboxylation of each of the following? Using curved arrows, represent the bond changes that take place at the transition state.

(a) (CH3)2C(CO2H)2

(b)

(c)

Sample Solution (a) Thermal decarboxylation of malonic acid derivatives leads to the replacement of one of the carboxyl groups by a hydrogen.

The transition state incorporates a cyclic array of six atoms:

Tautomerization of the enol form to 2-methylpropanoic acid completes the process.