Question

For each compound, predict the major product of free-radical bromination. Remember that bromination is highly selective, and only the most stable radical will be formed.

(a) cyclohexane

(b) methylcyclopentane

(c) decalin

(d) hexane

(e)

(f)

Short answer

a)

b)

c)

d)

e)

f)

Step-by-step solution

Free radicals

An atom or group of atoms containing odd or unpaired electron is known as the free radical. The unpaired electron is represented by a single unpaired dot in the formula. Free radicals are electrically neutral. They are highly reactive species formed by homolytic fission of a covalent bond.

Steps involved in free radical chain reaction

In a free-radical chain reaction, free radicals are generally created in the initiation steps. A free radical and a reactant is combined to yield a product and another free radical in the propagation steps. Lastly, the number of free radicals generally decrease in the termination steps.

Predicting the major product

Free-radical bromination is highly selective and only the most stable product will be formed.

(a)

Only one possible product is formed.

(b)

Tertiary radical is formed.

(c)

Tertiary radical is formed.

(d)

Secondary radical is formed.

(e)

Benzylic radical is formed.

(f)

Allylic radical is formed.