When 3,3-dimethylbutan-2-ol is treated with concentrated HBr , the major product formed is:

Step-by-step solution

The reaction proceeds via an S_N1 mechanism involving a carbocation intermediate. Protonation of the alcohol followed by the loss of a water molecule generates a secondary carbocation at C-2. CH₃-C(CH₃)₂-CH(OH)-CH₃ H^+ CH₃-C(CH₃)₂-CH^+-CH₃ + H₂O The less stable secondary carbocation undergoes a 1,2-methyl shift from the adjacent quaternary carbon (C-3) to form a more stable tertiary carbocation. CH₃-C(CH₃)₂-CH^+-CH₃ 1,2-methyl shift CH₃-C^+(CH₃)-CH(CH₃)-CH₃ Nucleophilic attack by the bromide ion ( Br^- ) on the ter