$\begin{array}{*{20}{c}}
O\\
{||}\\
{C{H_3} - C - C{H_3}}
\end{array}$ $ + \begin{array}{*{20}{c}}
{C{H_2}OH}\\
{\,\,\,\,|\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,}\\
{C{H_2}OH}
\end{array}$ $\overset{HCl}{\longleftrightarrow}$ ?

$\mathop {\begin{array}{*{20}{c}}
  {OH\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,O} \\ 
  {|\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,||} \\ 
  {C{H_2} = C - C{H_2} - C - C{H_3}} 
\end{array}}\limits_{(I)}  \rightleftharpoons $

$\mathop {\begin{array}{*{20}{c}}
  {OH\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,O} \\ 
  {|\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,||} \\ 
  {C{H_3} - C - C{H_2} - C - C{H_3}} 
\end{array}}\limits_{(II)}  \rightleftharpoons $

$\mathop {\begin{array}{*{20}{c}}
  {OH\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,O} \\ 
  {|\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,||} \\ 
  {C{H_3} - C = CH - C - C{H_3}} 
\end{array}}\limits_{(III)} $

$R - C \equiv N\xrightarrow[{(2)\,{H_2}O}]{{(1)\,AlH\,{{(i - Bu)}_2}}}$ ?