|Chapter 9 : Alkynes|
MECHANISM FOR THE REDUCTION OF ALKYNES WITH Na / NH3
Sodium transfers an electron to the alkyne giving a radical anion.
The radical anion removes a proton from the ammonia in an acid / base reaction.
A second atom of sodium transfers another electron to the alkyne giving a vinly carbanion. The stereochemistry is established at this step - the alkyl groups being trans.
The carbanion removes a proton from the ammonia in an acid / base reaction to give the trans-alkene.
|© Dr. Ian Hunt, Department of Chemistry, University of Calgary|