Alcohols, Phenols and Ethers

Major product formed in the following reaction is a mixture of : [figure]

1. [figure]
2. [figure]
3. [figure]
4. [figure]

Answer

(4) [figure]

Solution

HI first protonates the ether O. With a 3° alkyl group, the C–O bond breaks by SN1 to give the stable 3° carbocation:

[figure]

(CH3)3 C + I (CH3)3C-I

∵ (CH3)3 C (3°) is far more stable than a cyclohexyl (2°) cation, so I goes to the tert-butyl group and the ring keeps –OH.

∴ Cyclohexanol + tert-butyl iodide

Answer: (4)