Arrange the following carbonyl compounds in decreasing order of their reactivity towards nucleophili — Reaction Mechanism Chemistry Question
Question
Arrange the following carbonyl compounds in decreasing order of their reactivity towards nucleophilic addition reactions: Formaldehyde (I), Acetaldehyde (II), Acetone (III), Diethyl ketone (IV).
💡 Solution & Explanation
The rate of nucleophilic addition to carbonyl compounds decreases as steric hindrance at the carbonyl carbon increases. Alkyl groups also exert a $+I$ (electron-donating) effect, which reduces the electrophilicity (positive charge) of the carbonyl carbon. Therefore, aldehydes are generally more reactive than ketones, and smaller groups lead to higher reactivity. The correct order is Formaldehyde > Acetaldehyde > Acetone > Diethyl ketone.