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JEE Main levelSingle correct optionDifficulty 2 of 3o4155

2-Bromo-2-methylpropane is dissolved in 80% aqueous ethanol at 25 C with no added base. The main products are

  1. A2-methylpropene only
  2. B2-methylpropan-1-ol and 1-ethoxy-2-methylpropane
  3. C2-methylpropene and hydrogen only
  4. D2-methylpropan-2-ol and ethyl tert-butyl ether (substitution)

Answer: D

With only weakly basic polar protic solvent the SN1/E1 pathway operates via the tert-butyl cation. At low temperature capture of the cation by water or ethanol (substitution) predominates over proton loss, so alcohol and ether are the main products.
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