The major monobrominated product which results when methylcyclohexane is subjected to free radical bromination

Question

a. primary bromide

b. a tertiary bromide

c. bromomethane

d. a secondary bromide

e. a quarternary bromide

Answer 1

Answer is b.

The first step in free radical bromination is abstraction of a hydrogen from the organic compound.  The hydrogen with the lowest C-H bond energy will be abstracted.  A tertiary hydrogen has a slightly weaker bond energy than secondary, so the tertiary hydrogen is abstracted.  The resulting free radical combines with bromine to form a tertiary alkyl bromide.