Question

Aldol condensation is given by

• A. formaldehyde
• B. acetaldehyde
• C. trichloroacetaldehyde
• D. benzaldehyde.

Answer 1

Answer: (B)

Aldehydes and ketones having atleast one $\alpha$-hydrogen atom undergo a reaction in the presence of dilute alkali as catalyst to form $\beta$-hydroxy aldehydes (aldol) or $\beta$-hydroxy ketone? (ketol) respectively. This is known as aldol reaction. Benzaldehyde, formaldehyde and trichloroacetaldehyde do not give aldol condensation as they do not have $\alpha$-hydrogen atom