$(I)$ $C{H_2} = CH\mathop C\limits^ + HC{H_3}$
$\begin{array}{*{20}{c}}
{{\mkern 1mu} {\mkern 1mu} {\mkern 1mu} {\mkern 1mu} \,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,C{H_3}} \\
{\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,|\,\,} \\
{(II)\,\,\,\,\,\,\,\,\,\,C{H_2} = C - \mathop {{\text{ }}C}\limits^ + {H_2}}
\end{array}$
$(III)$ $C{H_3}CH = CH\mathop C\limits^ + {H_2}$
$[Nu^- = (1) PhO^- , (2) AcO^-, (3) HO^-, (4) CH_3O^-]$
$(x)\begin{array}{*{20}{c}}
{O\,\,\,}\\
{||\,\,\,}\\
{C{H_3} - S - O - H}\\
{||\,\,\,\,}\\
{O\,\,\,\,}
\end{array}$
$\begin{array}{*{20}{c}}
{\,\,\,\,\,O}\\
{\,\,\,\,\,\,||}\\
{(y)\,\,\,C{H_3} - C - O - H}
\end{array}$
$(z)\,\, CH_3 -OH$
$\mathop {C{H_3} - \mathop C\limits^ \oplus H - C{H_3}}\limits_I $
$\mathop {C{H_3} - \mathop C\limits^ \oplus H - OC{H_3}}\limits_{II} $
$\mathop {C{H_3} - \mathop C\limits^ \oplus H - C{H_2} - OC{H_3}}\limits_{III} $