$CH_3CH_2CH_2CH_2CH_2CH_3$ $(CH_3)_3 CCH_2CH_3$
$(CH_3)_2CHCH_2CH_2CH_3$ $(CH_3)_2CHCH(CH_3)_2$
$\begin{array}{*{20}{c}}
{C{H_3}C{H_2}CH - C{H_2}} \\
{\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,|\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,|} \\
{\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,Br\,\,\,\,\,\,\,\,\,Br\,\,}
\end{array}\xrightarrow[\begin{subarray}{l}
(ii)\,NaN{H_2} \\
in\,liq.\,N{H_3}
\end{subarray} ]{{(i)\,KOH\,alc.}}$