Reduction of alkynes to trans-alkenes via radical reaction
02:49 AM
4 / 10 / 2020
678
Author : University of Missouri System
Book or Source : Organic Chemistry ii
page : .................
Reduction of alkynes to trans-alkenes via radical reaction
Alkynes can be reduced to trans-alkenes with the use of sodium dissolved in an ammonia solvent. An Na radical donates an electron to one of the P bonds in a carbon-carbon triple bond. This forms an anion, which can be protonated by a hydrogen in an ammonia solvent. This prompts another Na radical to donate an electron to the second P orbital. Soon after this anion is also protonated by a hydrogen from the ammonia solvent, resulting in a trans-alkene.
R-C≡C-R + 2 Na in NH3 (liq) ——> trans R-CH=CH-R + 2 NaNH2
