Chemistry - STRUCTURAL ISOMERISM Question with Solution | TestHub

Hexan-3-one, $\mathrm{C}{\mathrm{H}}_3\mathrm{C}{\mathrm{H}}_2-\mathrm{CO}-\mathrm{C}{\mathrm{H}}_2\mathrm{C}{\mathrm{H}}_2\mathrm{C}{\mathrm{H}}_3$, has two different alpha positions. Enolisation at C-2 gives $\mathrm{C}{\mathrm{H}}_3-\mathrm{CH}=\mathrm{C}(\mathrm{OH})-\mathrm{C}{\mathrm{H}}_2\mathrm{C}{\mathrm{H}}_2\mathrm{C}{\mathrm{H}}_3$, whose double bond carries two different groups on each carbon, so it exists as E and Z forms. Enolisation at C-4 gives $\mathrm{C}{\mathrm{H}}_3\mathrm{C}{\mathrm{H}}_2-\mathrm{C}(\mathrm{OH})=\mathrm{CH}-\mathrm{C}{\mathrm{H}}_2\mathrm{C}{\mathrm{H}}_3$, which likewise exists as E and Z forms. Total = 2 + 2 = 4 enols.