JEE Main · 2025 · 04 Apr 2025 · Shift 1 · Haloalkanes and Haloarenes

Predict the major product of the following reaction sequence :-

(A)(see structure)
(B)(see structure)
✓ Correct
(C)(see structure)
(D)(see structure)

Answer: (B)

Solution

Free-radical bromination of methylcyclohexane with

B r_{2}

under light substitutes at the tertiary carbon to give 1-bromo-1-methylcyclohexane. Heating this with alcoholic

KOH

eliminates hydrogen bromide to form the more substituted alkene, 1-methylcyclohex-1-ene. Addition of

HBr

in the presence of peroxide then follows the anti-Markovnikov course, placing bromine on the less substituted ring carbon, so the major product is 1-bromo-2-methylcyclohexane.

JEE Main · 2025 · 04 Apr 2025 · Shift 1 · Single correct option

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