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JEE Advanced levelSingle correct optionDifficulty 3 of 3hx182

1-Bromo-4-chlorobenzene is treated with in dry ether, then with propanone, then , and the resulting alcohol is heated with concentrated . The final organic product is

  1. A1-bromo-4-(prop-1-en-2-yl)benzene
  2. B1-chloro-4-(propan-2-yl)benzene
  3. C2-(4-chlorophenyl)propan-2-ol
  4. D1-chloro-4-(prop-1-en-2-yl)benzene

Answer: D

Mg inserts into the weaker C-Br bond, giving ; the C-Cl bond stays. Addition to propanone gives 2-(4-chlorophenyl)propan-2-ol, a tertiary benzylic alcohol, which dehydrates with hot conc. to the alkene .
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