$C{H_3}\, - \,\,C{H_2}\, - \,\,C{H_2}\, - \,\,\mathop C\limits_{\mathop {||}\limits_{OHC\,\, - \,\,C\,\, - \,\,C{H_2}\, - \,\,C{H_3}} } \,\, - \,\,COOH$
$\begin{array}{*{20}{c}}
{\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,H\,\,\,\,\,{C_4}{H_9}} \\
{\,\,\,\,\,\,\,\,\,|\,\,\,\,\,\,\,\,\,|} \\
{C{H_3}C{H_2} - C - C - C{H_3}} \\
{\,\,\,\,\,\,\,\,|\,\,\,\,\,\,\,\,\,|} \\
{\,\,\,\,\,\,\,\,\,C{H_3}\,\,\,\,C{H_3}}
\end{array}$
$\begin{array}{*{20}{c}}
{\,\,\,\,\,\,\,C{H_3}} \\
{\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,|\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,} \\
{C{H_3} - C{H_2}C = CH - CHC{H_2}C{H_3}} \\
{|\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,} \\
{C{H_3}C{H_2} - CH - C{H_2}C{H_2}C{H_2}C{H_3}}
\end{array}$