Aldehydes that do not undergo aldol condensation are
(1) propanal (2) trichloroethanal (3) 2- phenylethanal (4) ethanal (5) benzaldehyde

Options

A. 3 and 4 only
B. 3 and 5 only
C. 1, 2 and 3 only
D. 2, 3 and 5 only

Answer

D

Explanation

The carbonyl compound must contain an `alpha`-hydrogen atom, for it to undergo aldol condensation. However, formaldehyde, though contains no `alpha`-hydrogen atom yet undergoes abnormal aldol condensation in presence of lime water.