$\begin{array}{*{20}{c}}
{\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,O} \\
{\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,||\,\,} \\
{C{H_3} - C}
\end{array}$ $ —\leftarrow$ $CH_2$ $ \rightarrow—$ $\begin{array}{*{20}{c}}
{\,\,\,\,\,\,O\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,} \\
{\,\,||\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,} \\
{C - C{H_3}\,\,\,\,\,\,\,\,\,\,\,\,}
\end{array}$ માં બે ઇલેકટ્રોન વીથડ્રોઈંગ સમૂહો ની આસપાસ છે જે તેને સક્રિય મિથીલીન સમૂહ બનાવે છે.
$(I)$ $\begin{array}{*{20}{c}}
O \\
{||} \\
{Ph\, - C - Ph}
\end{array}$
$(II)$ $\begin{array}{*{20}{c}}
{\,\,\,\,O} \\
{\,\,\,\,||} \\
{C{H_3} - C - H}
\end{array}$
$(III)$ $\begin{array}{*{20}{c}}
O \\
{||} \\
{C{H_3} - C - C{H_3}}
\end{array}$
is