


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

