Hydrocarbons

When sec-butylcyclohexane reacts with bromine in the presence of sunlight, the major product is :

1. [figure]
2. [figure]
3. [figure]
4. [figure]

Answer

(4) [figure]

Solution

Br• removes the H that gives the most stable radical (3° ≫ 2° ≫ 1°). The side-chain 3° radical has six α C–H (ring 3° radical: five) and is open, so it forms:

[figure]

∴ 2-bromo-2-cyclohexylbutane

Answer: (4)