Chemistry - Nomenclature Question with Solution | TestHub

The double bond carbons are ${\mathrm{C}}_1$ and ${\mathrm{C}}_2$. The $\mathrm{C}{\mathrm{H}}_3$ group should get the lowest locant, 3, so ${\mathrm{C}}_2$ must be the double bond carbon next to the $\mathrm{CH}(\mathrm{C}{\mathrm{H}}_3)$. That makes b = ${\mathrm{C}}_2$ and c = ${\mathrm{C}}_3$, so a is ${\mathrm{C}}_1$.