Question

provide the name of the cycloalkanes shown below using cis - trans nomenclature:
(i): cis - 1,6 - dibromocyclohexane; (ii): trans - 1,6 - dibromocyclohexane
(i): trans - 1,6 - dibromocyclohexane; (ii): cis - 1,6 - dibromocyclohexane
(i): cis - 1,2 - dibromocyclohexane; (ii): trans - 1,2 - dibromocyclohexane
(i): trans - 1,2 - dibromocyclohexane; (ii): cis - 1,2 - dibromocyclohexane

Explanation:

Step1: Understand cis - trans isomerism

Cis - isomers have two identical groups on the same side of the ring. Trans - isomers have two identical groups on opposite sides of the ring.

Step2: Analyze structure (i)

In structure (i), the two bromine atoms are on opposite sides of the cyclohexane ring, so it is trans - 1,2 - dibromocyclohexane.

Step3: Analyze structure (ii)

In structure (ii), the two bromine atoms are on the same side of the cyclohexane ring, so it is cis - 1,2 - dibromocyclohexane.

Answer:

D. (i): trans - 1,2 - dibromocyclohexane; (ii): cis - 1,2 - dibromocyclohexane