Question

Draw a stepwise mechanism for the following reaction

Short answer

The gem-diols would undergo hydration in acidic medium to give the corresponding carbonyl compound.

Consider the hydrolysis of the given gem-diol. One among the hydroxyl group is protonated in the acidic medium.

Protonation of diol

Step-by-step solution

Hydrolysis of diols

The gem-diols would undergo hydration in acidic medium to give the corresponding carbonyl compound.

Consider the hydrolysis of the given gem-diol. One among the hydroxyl group is protonated in the acidic medium.

Protonation of diol

Dehydration

The protonated hydroxy group leaves forming a cation. The cation is further stabilized by resonance.

Dehydration reaction

Deprotonation

The proton donates a pair of electrons for the pi-bond formation of the carbonyl compound.

Formation of ketone