MHT CET202521 Apr 2025Evening ShiftChemistryHydrocarbonsActual
Which of the following compounds is formed as major product in the following reaction. 2-methylbut-2-ene [ Peroxide ] HBr Product
Options
- A3-Bromo-2-methylbutane
- B2-Bromo-2-methylbutane
- C2-Bromo-3-methylbutane
- D2-Bromobutane
Correct answer
C. 2-Bromo-3-methylbutane
Step-by-step solution
Free radical addition of HBr to 2-methylbut-2-ene in the presence of peroxide follows the anti-Markovnikov pathway. The reaction proceeds via a radical mechanism initiated by peroxide. HBr adds across the double bond with the bromine radical attaching to the less substituted carbon to form a more stable tertiary radical intermediate. CH₃-C(CH₃)=CH-CH₃ + Br^ CH₃- C (CH₃)-CHBr-CH₃ The tertiary radical then abstracts a hydrogen from HBr to yield the final product. CH₃- C (CH₃)-CHBr-CH₃ + HBr CH₃-CH(CH₃)-CHBr-CH₃ + Br^