Question
2 - Hexyne gives $$trans$$ - 2 - Hexene on treatment with :
A.
$$Pt/{H_2}$$
B.
$$Li/N{H_3}$$
C.
$$Pd/BaS{O_4}$$
D.
$$LiAl{H_4}$$
Answer :
$$Li/N{H_3}$$
Solution :
Anti addition of hydrogen atoms to the triple bond occurs when alkynes are reduced with sodium ( or lithium ) metal in ammonia, ethylamine, or alcohol at low temperatures, This reaction called, a dissolving metal reduction, produces an $$\left( E \right) - $$ or $$trans$$ - alkene. Sodium in liq. $$N{H_3}$$ is used as a source of electrons in the reduction of an alkyne to a $$trans$$ alkene.
Anti addition of hydrogen atoms to the triple bond occurs when alkynes are reduced with sodium ( or lithium ) metal in ammonia, ethylamine, or alcohol at low temperatures, This reaction called, a dissolving metal reduction, produces an $$\left( E \right) - $$ or $$trans$$ - alkene. Sodium in liq. $$N{H_3}$$ is used as a source of electrons in the reduction of an alkyne to a $$trans$$ alkene.