$C{{H}_{3}}-C{{H}_{2}}-C\equiv N$ $\xrightarrow{{SnC{l_2}\,/\,HCl}}$ $C{H_3}C{H_2}CH = NH$
$\xrightarrow[{(Ether)}]{{{H_2}O\,,\,boil}}$ $C{H_3}C{H_2}CHO\, + \,N{H_4}Cl$
It is stephen's reduction.
$\begin{array}{*{20}{c}}
O\\
{||}\\
{C{H_3} - C - C{H_3}}
\end{array}$ $ + \begin{array}{*{20}{c}}
{C{H_2}OH}\\
{\,\,\,\,|\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,}\\
{C{H_2}OH}
\end{array}$ $\overset{HCl}{\longleftrightarrow}$ ?
$X-Y-Z$