The application of the reduction of aldehydes and ketones has been reviewed in an earlier chapter (The Meerwin-Pondorff-Verley reduction). The reversible nature of the reaction was demonstrated by Verley, but it was not until 1937 that Oppenauer showed that unsaturated steroid alcohols could be oxidized to the corresoponding ketones in excellent yield using aluminum t-butoxide. In the presence of a large amount of acetones. Acetone functions as the hydrogen acceptor and the large excess serves to shift the equilibrium into the desired direction. This reaction is called the Oppenauer reaction hand is useful in steroid chemistry. The Oppenauer oxidation employs mild conditions so it will undoubtedly find use in synthetic organic chemistry. The recent experimental modifications are discussed here.