Q. $\lbrack A\rbrack\underset{catalyst}{\overset{\ \ \ Lindlar^{'}s\ \ \ \ \ }{\leftarrow}}CH_{3} - C \equiv C - CH_{3}\underset{liq.NH_{3}}{\overset{\ \ \ \ \ Na\ in\ \ \ \ \ \ \ }{\rightarrow}}\lbrack B\rbrack$ [A] and [B] are respectively
A) $cis,\ trans$-2-butene
B) Both $trans$-2-butene
C) $trans,cis$-2-butene
D) Both $cis$-2-butene
Explanation
(a)
Alkynes give different products with different reducing agents $e.g.,$ with Lindlar’s catalyst $\left( \frac{Pd}{BaSO_{4}} \right)or\ Ni\ cis$-alkene is formed but with $Na\ in\ liquid\ NH_{3}$ (Birch reduction) $trans$ alkene is formed.
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Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.