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JEE Advanced levelOne or more correct optionsDifficulty 3 of 3o2110

3-Methylbut-1-ene is treated with HBr. Which statements are correct?

  1. AWith peroxide, the product is 1-bromo-3-methylbutane
  2. BIn the dark, rearrangement through a 1,2-hydride shift gives 2-bromo-2-methylbutane as the major product
  3. CWith peroxide, rearrangement of the intermediate to a tertiary species leads to 2-bromo-2-methylbutane
  4. DWith peroxide, the intermediate formed after addition is a secondary radical

Answer: A, B, D

With peroxide, adds to C-1 to give the secondary radical at C-2 and then 1-bromo-3-methylbutane forms; radicals do not undergo 1,2-hydride shifts under these conditions. In the dark, the secondary cation rearranges by a hydride shift to the tertiary cation, giving 2-bromo-2-methylbutane. So C is false.
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