The History of the Birch Reduction

The Birch Reduction was discovered by A.J. Birch in 1940 at the University of Oxford in England. This was during World War 2, and at the time, the Royal Air Force believed that German air pilots were being given cortical hormones to improve their performance.

The RAF wanted to replicate those hormones for their own pilots. The research team began by using female hormones, which are similar to male hormones but have a full aromatic ring as opposed to a partially hydrogenated one. Previous reactions had already demonstrated that the hydrogenated form of estrone (a weak estrogen) was a weakly active male sex hormone.

Birch was able to use findings from a series of past procedures to conclude that the simultaneous acting of a strong electrophile and an -OH group attached to a carbon group would produce a dihydrogenated benzene. This reaction produced a desired potent synthetic androgen. This process was later used for synthesis of many other compounds.

A. J. Birch J. Chem. Educ. 1975, 52, 458.