Chemistry - STRUCTURAL ISOMERISM Question with Solution | TestHub

For tautomerism, the compound must have a mobile $\alpha$-H (or suitable tautomerizable H) adjacent to the functional group.

(i) No $\alpha$-H is present next to C=O.

(ii) $\alpha$-H is present; keto–enol tautomerism is possible.

(iii) $\alpha$-H is present on the cyclohexyl side; tautomerism occurs.

(iv) No suitable $\alpha$-H is available.

(v) Nitroso–aci-nitro tautomerism is possible.

(vi) No suitable tautomerizable $\alpha$-H.

(vii) Both aldehyde groups have $\alpha$-CH₂​, so tautomerism is possible.

Number of compounds = 4

Correct: (ii), (iii), (v), (vii)