Chemistry - Nomenclature Question with Solution | TestHub

The ring carries two adjacent methyl groups and one ethyl group. Number the ring so that the set of locants is the lowest possible.

Numbering from one methyl carbon through the other gives {1,2,4}, against {1,2,5} in the other direction or {1,3,4} when the ethyl carbon is ${\mathrm{C}}_1$. The lowest set is {1,2,4}, with the ethyl group at ${\mathrm{C}}_4$.

Name (alphabetical order): 4-ethyl-1,2-dimethylcyclohexane.