d
\(\mathop {C{H_3}CHO}\limits_{(X)} \) \(+\) \(\mathop {\mathop {{H_3}C - CHO}\limits_{(Y)} }\limits^\infty \) (એસિટાલ્ડીહાઇડ ) \(\to \) \(\begin{array}{*{20}{c}}
{OH\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,} \\
{|\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,} \\
{C{H_3} - CH - C{H_2} - CHO}
\end{array}\)
( \( 3-\) હાઇડ્રોક્સી બ્યુટેનાલ)