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JEE Advanced levelOne or more correct optionsDifficulty 3 of 3o4125

2-Bromo-3-methylbutane is heated in ethanol with no added base. Which statements are correct?

  1. AThe major alkene is 2-methylbut-2-ene.
  2. B2-Ethoxy-2-methylbutane is a substitution product.
  3. C3-Methylbut-1-ene is the major alkene.
  4. DA 1,2-hydride shift converts the secondary cation into a tertiary cation.

Answer: A, B, D

Ionisation gives the secondary cation , which undergoes a 1,2-H shift to the more stable tertiary cation. This cation loses a proton (Saytzeff) to give 2-methylbut-2-ene, or is captured by ethanol to give 2-ethoxy-2-methylbutane. 3-Methylbut-1-ene is at most a minor product.
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