$\begin{array}{*{20}{c}}
{\,\,\,\,\,\,C{H_3}} \\
| \\
{C{H_3} - C - OH} \\
| \\
{\,\,\,\,\,\,C{H_3}}
\end{array}\, \to \begin{array}{*{20}{c}}
{\,\,\,C{H_3}} \\
| \,\,\,\,\\
{C{H_3} - {C^ \oplus } - O{H^ - }} \\
| \,\,\,\,\\
{C{H_3}}
\end{array}$
$3^o$ કાર્બોનિયમ આયન
$\begin{array}{*{20}{c}}
{OH\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,} \\
{|\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,} \\
{C{H_3}CHC{H_2}C{H_2}N{H_2}}
\end{array}$ $\xrightarrow[{triethyla\min e}]{{ethyl\,formate\,\left( {1\,equiv} \right)}}$