Question

Which of the following halides would undergo nucleophilic substitution more readily?

• A. 1-Chloro-1-butene
• B. 2-Chloro-1-butene
• C. 3-Chloro-1-butene
• D. 4-Chloro-1-butene

Answer 1

The correct option is C 3-Chloro-1-butene

As in this nucleophilic substitution reaction, compounds follow $S{N}^1$ mechanism and allylic carbocation is most stable among all so $3$-chloro-$1$-butene is most reactive.

For $S{N}^1$ reactions, formed allylic carbocation is most stable among all so correct order of reactivity is allyl chloride > alkyl chloride >vinyl chloride.

Option C is correct.