Birch Reduction

Birch Reduction

A terminal double bond may be reduced by sodium in liquid ammonia in the presence of an alcohol (MeOH or EtOH; alcohols are stronger acids than ammonia). This method is known as the Birch reduction, and is believed to proceed stepwise via an anionic free radical:

The double bond is also reduced in excellent yield by NaBH₄-PtCl₂ (Brown et al., 1962)