$Ph - C \equiv C - Ph \to $
\(Ph-C\equiv C-Ph\xrightarrow[Brich\,reduction]{Li\,in\,liq.N{{H}_{3}}}\begin{matrix}
^{Ph} \\
_{H} \\
\end{matrix}\begin{matrix}
\text{ }\!\!\backslash\!\!\text{ } \\
/ \\
\end{matrix}C=C\begin{matrix}
/ \\
\text{ }\!\!\backslash\!\!\text{ } \\
\end{matrix}_{Ph}^{H}\)
$C{H_2} = CH - C{H_3} + HBr \to C{H_3}CHBr - C{H_3}$
${C_6}{H_5}C{H_3}\xrightarrow{{Oxidation}}A\xrightarrow{{NaOH}}B\xrightarrow[\Delta ]{{sodalime}}C$