back to directory
NEET CHEMISTRYAlcohols, Phenols and EthersMedium

Question

Consider the following reaction and identify the product (P): [Specific Reaction Image Missing - Likely Reaction of 3-Methylbutan-2-ol with HBr]

A

2-Bromo-3-methylbutane

B

2-Bromo-2-methylbutane

C

2-Methylbut-2-ene

D

1-Bromo-2-methylbutane

Step-by-Step Solution

The reaction of a secondary alcohol with a hydrogen halide (like HBr) proceeds via an SN1S_N1 mechanism involving a carbocation intermediate:

  1. Protonation: The -OH group accepts a proton (H+H^+) to form water (H2OH_2O), which is a good leaving group.
  2. Carbocation Formation: Water leaves, generating a secondary (22^{\circ}) carbocation (e.g., from 3-methylbutan-2-ol, a 22^{\circ} carbocation is formed).
  3. Rearrangement: A less stable carbocation rearranges to a more stable one if possible. Here, a 1,2-hydride shift occurs, converting the secondary carbocation into a more stable tertiary (33^{\circ}) carbocation.
  4. Nucleophilic Attack: The bromide ion (BrBr^-) attacks the stable tertiary carbocation to form the major product, 2-Bromo-2-methylbutane (Tertiary Alkyl Halide).

Direct attack on the secondary carbocation yields the minor product.

Exam Context & Concepts Covered

This question aligns with the NEET CHEMISTRY syllabus, specifically targeting concepts from Alcohols, Phenols and Ethers. Mastering this topic is crucial for scoring well in the upcoming medical entrance examinations. Solving conceptually related problems will help you understand the nuances of these concepts and improve your problem-solving speed.

CHEMISTRYAlcohols, Phenols and Ethersconsiderfollowingreactionidentifyproduct

More Alcohols, Phenols and Ethers Questions

View all

This neet chemistry practice question is part of the TopperSquare free question bank. TopperSquare offers 15,000+ chapter-wise NEET MCQs across Physics, Chemistry, and Biology with detailed step-by-step explanations, full mock tests, NEET PYQs (2010–2024), and an AI-powered performance analytics dashboard. browse all neet practice questions → · practice chemistry sets →