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JEE Advanced levelOne or more correct optionsDifficulty 3 of 3o4085

2-Bromo-2-methylbutane is subjected to three conditions. Select all correct statements.

  1. AIn ethanol at with no added base, the main product is 2-ethoxy-2-methylbutane, with alkenes as minor products.
  2. BWith in ethanol, the major alkene is 2-methylbut-2-ene, formed by E2.
  3. CWith in , the major product is 2-methylbut-1-ene.
  4. DIn ethanol with no added base, 2-methylbut-1-ene is the major alkene because ethanol is a bulky base.

Answer: A, B, C

Without a strong base the substrate ionises (SN1/E1) and the cation is captured by solvent ethanol more often than it loses a proton, so the ether predominates. With unhindered ethoxide, E2 follows Saytzeff orientation. With the bulky tert-butoxide, Hofmann orientation gives 2-methylbut-1-ene. Ethanol is neither a bulky nor a strong base, and in E1 the Saytzeff alkene is favoured, so the fourth statement is false.
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