Question

Alkynes on reduction with sodium in liquid ammonia form trans alkenes. Will the butene thus formed on reduction of 2-butyne show the geometrical isomerism?

Answer 1

\[\begin{array}{cc}
\phantom{....................................}\ce{H3C}\phantom{........}\ce{H}\phantom{.}\\
\phantom{......................................}\backslash\phantom{......}/\phantom{.}\\
\ce{H3C - C = C - CH3 + H2 ->[Na/liq.NH3] C = C}\\
\phantom{.....................................}/\phantom{......}\backslash\phantom{}\\
\phantom{.......................................}\ce{\underset{trans-But-2-ene}{\phantom{.}H\phantom{........}CH3}}\phantom{.}
\end{array}\]

Thus, but-2-ene is capable of showing geometrical isomerism.