Ethylbenzene is heated with $Br X_{2}$ under light to give X (major). X is heated with alcoholic KOH to give Y. Y is treated with $HBr$ in the presence of an organic peroxide to give Z. Z is:

A(2-Bromoethyl)benzene
B(1-Bromoethyl)benzene
C1-Bromo-2-ethylbenzene
D1-Bromo-4-ethylbenzene

Answer: A

Radical bromination occurs selectively at the benzylic position to give X, (1-bromoethyl)benzene. Dehydrohalogenation gives styrene, Y. Peroxide-induced radical addition of HBr puts

Br \cdot

on the terminal carbon to give the benzylic radical, so Z is

C X_{6} H X_{5} - CH X_{2} - CH X_{2} Br

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Ethylbenzene is heated with BrX2​ under light to give X (major). X is heated with alcoholic KOH to give Y. Y is treated with HBr in the presence of an organic peroxide to give Z. Z is:

Answer: A

More questions on Aromatic hydrocarbons: benzene reactions and side chain reactions

Ethylbenzene is heated with $Br X_{2}$ under light to give X (major). X is heated with alcoholic KOH to give Y. Y is treated with $HBr$ in the presence of an organic peroxide to give Z. Z is: