Which of th efollowing alcohols are excepted to react with hydrogen halides by both `S_(N)1` and `S_(N)2` mechanisms ?

Options

A. `t`-Alcohols
B. Straight -chain primary alcohols
C. Branded chain primary alcohols
D. Secondary alcohols

Answer

D

Explanation

The nature of an alkyl group influences the mechanism of halide formation in the same way as it does their hydrolysis.
Protonated `3^(@)` alcohols readily eliminate a molecular of water to form a carbocation and so react by the `S_(N)1` mechanism. Straight -chain primary alcohols will favour the `S_(N)2` mechanism , but if branched chain , then the `S_(N)1` mechanism may operate (e.g. neopentyl alcohol). Secondary alcohols would be expected to reach by both mechanisms.