Question

Choose the correct statement related to (I) and (II)

• A. (I) has more enol content than (II)
• B. (II) has more enol content than (I)
• C. Both (I) anf (II) has similar enol content
• D. Both (I) and (II) does not exhibit Keto-enol tautomerism

Answer 1

The correct option is A (I) has more enol content than (II)

In Keto-enol tautomerism, delocalisation takes place between a >C=O group and an alpha H where the equilibrium lies between a keto form and an enol form.
Enol form of (I) has 6-$\pi$ electrons which obeys the (4n+2) pi Huckel's rule. Hence, the enol form becomes aromatic and thus it is more stable than its Keto form.
Enol form of (II) does not have any aromaticity for stabilisation of enol form. Hence, in (II) keto form is more stable than enol form.
Therefore, (I) has more enol content than (II).