Question

How might you prepare each of the following molecules using a nucleophilic substitution reaction at some step?

(a)

Short answer

$C{H}_{3}Br+N{a^{+}}^{-}C\equiv CH{\left(C{H}_3\right)}_2\to C{H}_{3}C\equiv CH{\left(C{H}_3\right)}_2+NaBr$

Step-by-step solution

SN2reaction

It is a nucleophilic substitution reaction in which an old bond breaks and a new bond is formed both processes occur simultaneously. Hence, it’s a single-step reaction.

Formation of CH3C≡CHCH32

Here, nucleophilic substitution occurs where NaBr is produced and desired product is formed.$C{H}_{3}Br+N{a}^{+}{C}^{-}\equiv CH{\left(C{H}_3\right)}_2\to C{H}_{3}C\equiv CH{\left(C{H}_3\right)}_2+NaBr$