$\begin{array}{*{20}{c}}
{OH\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,} \\
{|\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,} \\
{C{H_3}CHC{H_2}C{H_2}N{H_2}}
\end{array}$ $\xrightarrow[{triethyla\min e}]{{ethyl\,formate\,\left( {1\,equiv} \right)}}$