question_answer

IUPAC name of   is

A)  1 -methyl-3 ethyl cyclohexane

B)  1 -ethyl-3 methyl benzene

C)  1 -ethyl-3 methyl cycio hexane

D)  Cycio hexane-1 -ethyl-3-methyl

Correct Answer: D

Solution :

Ethyl group comes first in alphab- atical order but IUPAC name of 2-bromo-4-ethyl-l-methyl cyclohexane. It follows lowest sum rule (i.e., lowest set of locant is preferred.) Lowest sum of locant is\[~=1+2+3=6\]