The reaction proceeds via an \( S_N1 \) mechanism where the chlorine group leaves, forming a carbocation.
After the formation of the carbocation, a 1,2-hydride shift occurs to stabilize the carbocation, resulting in a more stable tertiary carbocation.
Subsequent attack by hydroxide ion (\( \text{OH}^- \)) leads to the formation of the major product:
The major product is a tertiary alcohol.