Question

Which one of the following esters cannot undergo Claisen self-condensation?

(a) C₆H₅CH₂COOC₂H₅

(b) C₆H₅COOC₂H₅

(c) CH₃CH₂CH₂CH₂COOC₂H₅

(d) C₆H₁₁CH₂COOC₂H₅

Answer 1

The correct option is: (b) C₆H₅COOC₂H₅

Explanation:

The esters having active methylene group (- CH₂ -), show Claisen Condensation reaction. As C₆H₅- COOC₂H₅ has no α-hydrogen atom or active methylene group, so it cannot undergo Claisen- Condensation reaction.