Illustrated Glossary of Organic Chemistry

Dissolving metal reduction: A reduction reaction in which a metal (the reducing agent) dissolves in the solvent during the course of the reaction.

Birch reduction is a type of dissolving metal reduction. The reaction sequence begins with dissolution of an alkali metal such as lithium in liquid ammonia, to produce a deep blue solution. The color is due to free electrons solvated by a shell of ammonia molecules. Click the image to watch the video.


Addition of tert-butanol and methyl benzoate to the Li/NH₃ solution causes reduction of the benzene ring to a 1,4-diene.