$\begin{matrix}
O\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\, \,\, \\
||\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\, \\
N\equiv C-C{{H}_{2}}-C-C{{H}_{2}}-CH=C{{H}_{2}}\to \\
\end{matrix}$ $\begin{matrix}
OH\,\,\,\,\,\,\,\,\, \\
|\,\,\,\,\,\,\,\,\, \,\,\,\, \\
N\equiv C-C{{H}_{2}}-\underset{H}{\mathop{C}}\,-C{{H}_{2}}-CH=C{{H}_{2}} \\
\end{matrix}$
$\begin{array}{*{20}{c}}
{\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,OH} \\
{\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,|\,\,} \\
{C{H_3} - CH = CH - C{H_2} - CH - C{H_3}}
\end{array}$ $\longrightarrow $ $C{H_3} - CH = CH - C{H_2}C{O_2}H$
$\mathop {{C_2}{H_5}OH}\limits_{\left( I \right)} $ $\mathop {{C_2}{H_5}Cl}\limits_{\left( {II} \right)} $ $\mathop {{C_2}{H_5}C{H_3}}\limits_{\left( {III} \right)} $ $\mathop {{C_2}{H_5}OC{H_3}}\limits_{\left( {IV} \right)} $