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Consider the following reaction sequence: 1,2-dibromo-3,3-dimethylcyclohexane (i) Zn, Intermediate (ii) HCl Major Product (P) The major product (P) is:

Options

  1. A2-chloro-3,3-dimethylcyclohexane
  2. B1-chloro-3,3-dimethylcyclohexane
  3. C1-chloro-2,2-dimethylcyclohexane
  4. D1-chloro-1,2-dimethylcyclohexane

Correct answer

D. 1-chloro-1,2-dimethylcyclohexane

Step-by-step solution

Treatment of 1,2-dibromo-3,3-dimethylcyclohexane with Zn dust and heat causes dehalogenation, yielding 3,3-dimethylcyclohexene. Addition of HCl begins with the protonation of the alkene. Protonation at C1 generates a secondary carbocation at C2, which is adjacent to the quaternary C3 carbon. To achieve greater stability, a 1,2-methyl shift occurs from C3 to C2, transforming the secondary carbocation into a more stable tertiary carbocation at C3. Finally, the chloride ion attacks this tertiary carbocation, resulting

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