$C{H_2} = C{H_2}\, \xrightarrow{{HOCl}} \,A\xrightarrow{{_R}}\begin{array}{*{20}{c}} {C{H_2}OH} \\ {|\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,} \\ {C{H_2}OH} \end{array}$