Exams › JEE Advanced › Chemistry
Which of the following reagents or reaction conditions would give 2-bromo-1-phenylpropane (C6H5CH2CHBrCH3) as the product?
- C6H5CH2CH(OH)CH3 treated with PBr3
- C6H5CH=CHCH3 treated with HBr in the presence of benzoyl peroxide
- C6H5CH2CH2CH3 treated with Br2 under UV light
- None of these
Correct answer: C6H5CH2CH(OH)CH3 treated with PBr3
Solution
PBr3 converts secondary alcohols to alkyl bromides via an SN2-like mechanism. C6H5CH2CH(OH)CH3 has the hydroxyl at the correct position; replacement with Br gives 2-bromo-1-phenylpropane directly. Option B (anti-Markovnikov HBr addition) would put Br at C-1 of the alkene, giving C6H5CHBrCH2CH3 (1-bromo-1-phenylpropane). Option C gives radical bromination at the benzylic position predominantly.
Related JEE Advanced Chemistry questions
- When hydrogen halides react with alcohols, alkyl group rearrangement does not typically happen with most primary alcohols. What is the most accurate reason for this?
- Which of the following statements accurately describes the behavior of the given compound?
- Tertiary and secondary carbocations readily participate in elimination reactions when treated with strong alkoxide bases, while aryl and vinyl halides resist nucleophilic substitution. Which of the following reactions is correct?
- Although neopentyl alcohol is a primary alcohol, it follows the SN1 mechanism due to steric hindrance caused by a bulky alkyl group. Identify its structure.
- In the following sequence of reactions, identify the structures of intermediates Y, Z, W, and M: Y --(NaBH4)--> Z --(conc. HBr)--> W Y --(N2H4 / KOH, heat)--> M M --(NBS, heat/light)--> W W --(1) Mg/ether, (2) CO2, (3) H3O+)--> Ph-CH(COOH)-CH2-CH3 Which of the following statements about the intermediates is correct?
- Consider the compound CH3-CH2-CH(X)-CH3, where X is a halogen. When treated with alcoholic KOH and heated, it undergoes elimination to give alkene products. For which choice of X will the proportion of the Hofmann (less substituted) alkene product be the greatest?
⚔️ Practice JEE Advanced Chemistry free + battle 1v1 →