Question

A mixture of cinnamaldehyde and crotonaldehyde is treated with concentrated alkali,

Which statement is not true about the above reaction?

• A. Aldol condensation takes place and $\alpha$-carbon atom of crotonaldehyde provides the carbanion.
• B. Aldol condensation takes place and $\gamma$-carbon atom of crotonaldehyde provides the carbanion.
• C. Aldol condensation takes place and $\beta$-carbon atom of crotonaldehyde provides the carbanion.
• D. Aldol condensation takes place and product will be saturated carbonyl compound.

Answer 1

Answer: (A), (C), (D)

Removal of $\gamma$-hydrogen of crotonaldehyde provides more stable allylic carbanion, hence here $\gamma$-carbon (not $\alpha$ ) provides the carbanion (nucleophile) for carbonyl carbon of cinnamaldehyde.