$n - Bu -\equiv\frac{(i) n-BuLi,n - C _{5} H _{11} Cl}{(ii) Lindlar\,\, cat, H _{2}}$
$\begin{array}{*{20}{c}}
{C{H_3}C{H_2}CH - C{H_2}} \\
{\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,|\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,|} \\
{\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,Br\,\,\,\,\,\,\,\,\,Br\,\,}
\end{array}\xrightarrow[\begin{subarray}{l}
(ii)\,NaN{H_2} \\
in\,liq.\,N{H_3}
\end{subarray} ]{{(i)\,KOH\,alc.}}$