Question

Which of the following will not give aldol condensation?

• A. Phenyl acetaldehyde
• B. Benzaldehyde
• C. 1-Phenylpropanone

Answer 1

The correct option is B Benzaldehyde

An aldol condensation is a condensation reaction in which an enol or an enolate ion reacts with a carbonyl compound to form a $\beta$-hydroxyaldehyde or $\beta$-hydroxyketone, followed by dehydration to an $\alpha ,\beta$-unsaturated aldehyde.
Aldol condensation occurs in aldehydes having $\alpha$-hydrogen.
Benzaldehyde does not have $\alpha$-hydrogen thus it will undergo aldol condensation. Hence correct option is (c).