Birch reduction

Birch reduction
Named after	Arthur Birch
Reaction type	Organic redox reaction
Identifiers
Organic Chemistry Portal	birch-reduction
RSC ontology ID	RXNO:0000042

The Birch reduction is an organic reaction which is particularly useful in synthetic organic chemistry. The reaction was reported in 1944 by the Australian chemist Arthur Birch (1915–1995) working in the Dyson Perrins Laboratory in the University of Oxford, building on earlier work by Wooster and Godfrey in 1937. It converts aromatic compounds having a benzenoid ring into a product, 1,4-cyclohexadienes, in which two hydrogen atoms have been attached on opposite ends of the molecule. It is the organic reduction of aromatic rings in liquid ammonia with sodium, lithium or potassium and an alcohol, such as ethanol and tert-butanol. This reaction is quite unlike catalytic hydrogenation, which usually reduces the aromatic ring all the way to a cyclohexane.

The original reaction reported by Arthur Birch in 1944 used sodium and ethanol.Alfred L. Wilds later discovered that lithium gives better yields. Also the use of t-butyl alcohol has become common. The reaction is widely used in synthetic organic chemistry.

An example is the reduction of naphthalene:

Several reviews have been published.

...
Wikipedia