$\begin{array}{*{20}{c}}
{\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,H\,\,\,\,\,{C_4}{H_9}} \\
{\,\,\,\,\,\,\,\,\,|\,\,\,\,\,\,\,\,\,|} \\
{C{H_3}C{H_2} - C - C - C{H_3}} \\
{\,\,\,\,\,\,\,\,|\,\,\,\,\,\,\,\,\,|} \\
{\,\,\,\,\,\,\,\,\,C{H_3}\,\,\,\,C{H_3}}
\end{array}$