Arrange the following compounds in the decreasing order of their reactivity towards reduction by LiAlH ₄ : (I) (II) (III)

Step-by-step solution

The reduction of carbonyl compounds by LiAlH ₄ involves the nucleophilic attack of a hydride ion ( H ⁻ ) on the electrophilic carbonyl carbon. The reactivity of the carbonyl group towards nucleophilic attack depends on the magnitude of the positive charge (electrophilicity) on the carbonyl carbon. This is influenced by the inductive and resonance effects of the attached groups. In acetyl chloride (II), the highly electronegative - Cl atom exerts a strong -I effect, which increases the positive charge on the carbony