Why this decarboxylation of 3 chloro 4 oxo pentanoic acid gives no reaction

Question

Why decarboxylation is not possible? 

Answer 1

Hello Mukul

 

Decarboxylation of β-keto acids occur when the oxo group is on the β-carbon from the carboxylic acid carbon. In 3-chloro-4-oxo-pentanoic acid, the oxo group is on the 3rd (γ, gamma) carbon from the carboxylic acid carbon.

 

CH₃-CO-CHCl-CH₂-COOH

         γ     β       α

 

β-keto acids undergo decarboxylation via a resonance stabilized enolate anion, which is formed at the α-carbon and the adjacent oxo group at the β position.

 

In 3-chloro-4-oxo-pentanoic acid, the enolate does not form since the oxo group is one carbon further away from the β position resulting in no decarboxylation reaction.