a
\(\mathop {\begin{array}{*{20}{c}}
{\,OH} \\
{|\,\,\,\,} \\
{C{H_3} - CH - C{H_3}}
\end{array}}\limits_{(2\, - \,propanol)} \) \(\xrightarrow {cu/300\,^oC}\) \({\mkern 1mu} \mathop {\begin{array}{*{20}{c}}
O \\
{||} \\
{C{H_3} - C - C{H_3}}
\end{array}}\limits_{(acetone)} \)