When pinacol is treated with dilute H_(2)SO_(4), a re-arangement reaction takes place which leads to the formation of a ketone. CH_(3)-underset(CH_(3))underset(|)overset(OH)overset(|)C-underset(CH_(3))underset(|)overset(OH)C-CH_(3)overset(H_(2)SO_(4))rarrCH_(3)-underset(CH_(3))underset(|)overset(O)overset(||)C-overset(CH_(3))overset(|)C-CH_(5) This reaction involves re-arrangement of carbocation Step 1: CH_(3)-underset(CH_(3))underset(|)overset(OH)overset(|)C-underset(CH_(3))overset(+)overset(OH_(2))overset(|)C-CH_(2)rarrCH_(3)-underset(CH_(3))underset(|)overset(OH)overset(|)C-underset(CH_(3))underset(|)overset(OH)overset(|)C-underset(CH_(3))underset(|)overset(+)C-CH_(3) Step 2: Carbocation rearrange by hydride, alkyl shift to get as stable as they can. Stability is the driving force for re-arrangement migration of bond may also oC Cur. Where by ring expansion and ring contraction takes place. The relief of strain can provide a powerful driving force for re-arrangement. What will be the product of following reaction CH_(3)-underset(H)underset(|)overset(OH)overset(|)C-underset(H)underset(|)overset(OH)overset(|)CH_(3)overset(H_(2)SO_(4))rarrQ Q is: