Which of the following reaction`(s)` can be used for the preparation of alkyl halides?
(I) `CH_(3)CH_(2)OH+HCloverset(anhy.ZnCl_(2))(rarr)`
(II) `CH_(3)CH_(2)OH+HClrarr`
(III) `(CH_(3))_(3)COH+HClrarr`
(IV) `(CH_(3))_(2)CHOH+HCloverset(anhy.ZnCl_(2))(rarr)`

Options

A. `(IV)` only
B. `(III)` and `(IV)` only
C. `(I), (II)` and `(IV)` only
D. `(I)` and `(II)` only

Answer

C

Explanation

`HCl` reacts with `1^(@)` and `2^(@)` alcohols to yield the corresponding chloride only in the presence of anhydrous `ZnCl_(2)`,
Thus `(I)` and `(IV)` can be used due to presence of anhydrous `ZnCl_(2)`, while `(III)` gives alkyl halide due to formation of more stable carboncation.