Aspects of stereochemistry. Part XXI. Hydrogenation of 3-oxo-Δ4-steroids over a palladium–calcium carbonate catalyst

Abstract
The stereochemistry of the addition of hydrogen (from a palladium–calcium carbonate catalyst) to the 4,5-bond in 3-oxo-Δ4-steroids is influenced by the presence and the nature of a substituent at C-17 and by the solvent.