Question

Arrange the following carbonyl compounds in increasing order of their reactivity in nucleophilic addition reaction.
Benzaldehyde, p-tolualdehyde, p-nitrobenzaldehyde, acetophenone.

Answer 1

$e^{-}$ density at carbonyl carbon increases with increase in the $+I$ effect. The $+I$ effect is more in ketone than aldehyde.

Hence, the increasing order of reactivity is:-

Acetophenone $<$ p-tolualdehyde $<$ Benzaldehyde $<$ p-Nitrobenzaldehyde