Chemistry - Carbonyl compounds Question with Solution | TestHub

Question Explanation:

The reaction involves dehydration and rearrangement of a 1,2-diol (vicinal diol) under acidic conditions. Concept:

This is a classic Pinacol–Pinacolone rearrangement , where a vicinal diol undergoes acid-catalyzed dehydration followed by a 1,2-shift to form a ketone.

Solution:

In acidic medium, one –OH group gets protonated and leaves as H₂O , forming a carbocation.

To stabilize this carbocation, a 1,2-methyl shift occurs (methyl migrates preferentially due to 2 better carbocation stabilization).

Simultaneously, the remaining –OH group converts into a carbonyl (C=O) .

Finally, deprotonation gives the rearranged ketone (pinacolone derivative) .