Question

Which of the following reaction(s) follow $S_{N}1$ mechanism?

• A. Reaction of diazonium salt with water
• B. Reaction of tert-butyl alcohol with $HI$
• C. Reaction of Prop-2-en-1-ol with $HI$
• D. All of the above.

Answer 1

The correct option is D All of the above.

Reaction of Diazonium Salt with Water:

$\underset{\text{Diazonium salt}}{R-N_2^{+}{X}^{-}}+H_{2}O\to \underset{\text{Alkyl alcohol}}{R-OH}+N_2\uparrow +HX$

Here displacement of diazo group by $-OH$ group takes place by $S_{N}1$ mechanism and carbocation formed as an intermediate.

Other reactions following $S_{N}1$ mechanism:
Reactions of higher alcohols with $HI$:

Reaction of tert-butyl alcohol with $HI$



Reaction of Prop-2-en-1-ol with $HI$: