Fast reactions in liquids

Fig. 3. Transferring reaction mixtures in liquid ammonia under ice. Fig. 4. Fast reactions in liquid ammonia.

Case C Fast reaction in liquid film, with low... 

If the lithium reduction is carried out in liquid ammonia without any acidic co-solvents, the enolate anion C is stable and remains unchanged until an electrophilic reagent such as R-X is added. If an acidic co-solvent such as ethanol is present, the enolate anion C is protonated, and the resulting ketone D is then reduced to an alcohol. Although the radical anion intermediate C usually undergoes protonation at the P-carbon, this is not a fast reaction in liquid ammonia. 

Jonah,C.O., Techniques for the Study of Fast Reactions in Liquids, This Volume. 

---