$C{H_2} = C{H_2}\xrightarrow{{HBr}}X\xrightarrow{{{\text{Hydrolysis}}}}Y\mathop {\xrightarrow{{N{a_2}C{O_3}}}}\limits_{{I_2}{\text{ excess}}} Z$
$C{{H}_{3}}\,-\,\,\overset{\overset{C{{H}_{3}}}{\mathop{|}}\,}{\mathop{C}}\,H\,\,-\,\,C{{H}_{3}}(excess)\,\,+\,\,B{{r}_{2}}\,\xrightarrow{hv}$
$\,\,\,\,C{{H}_{3}}\,-\,\,\overset{\overset{C{{H}_{3}}}{\mathop{|}}\,}{\mathop{\underset{\underset{Br}{\mathop{|}}\,}{\mathop{C}}\,}}\,\,\,-\,\,C{{H}_{3}}\,+\,\,C{{H}_{3}}\,-\,\,CH\,\,-\,\,C{{H}_{2}}\,-\,\,Br$

$\begin{array}{*{20}{c}}
{C{H_3}C{H_2}CH - C{H_2}} \\
{\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,|\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,|} \\
{\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,Br\,\,\,\,\,\,\,\,\,Br\,\,}
\end{array}\xrightarrow[\begin{subarray}{l}
(ii)\,NaN{H_2} \\
in\,liq.\,N{H_3}
\end{subarray} ]{{(i)\,KOH\,alc.}}$
