Question

Draw the major organic product from reaction of 2-butyne with li in nh3.

Answer 1

Alkynes can be reduced to trans-alkenes using Li(lithium) in NH₃(ammonia).
Lithium is a reducing agent.
In this case product is trans-2-butene.
Reaction:
CH₃-C≡C-CH₃ (2-butyne)   +   2 Li   in   NH₃ (liq)   ——> 
trans CH₃-CH=CH-CH₃   +   2 LiNH₂ (lithium-amide).