$\,{H_3}C\, - \,\,\mathop C\limits^{\mathop {||}\limits^O } \,\, - \,\,\mathop C\limits^{\mathop |\limits^{OH} } H\,\, - \,\,\mathop C\limits^{\mathop |\limits^{N{O_2}} } H\,\, - \,\,C{O_2}H$
$\begin{matrix} C{{H}_{3}}\,\,\,\,\,\,\, \\ |\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\, \\ {{H}_{3}}C-C-CH=C{{H}_{2}} \\ |\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\, \\ C{{H}_{3}}\,\,\,\,\,\,\,\,\, \\ \end{matrix}$