Crystallographic and spectroscopic study on a known orally active progestin

Conformational and stereochemical characterization of 6,17α-dimethyl pregnan-4,6-dien-3-one (medrogestone, red) and its precursor 17α-methyl-3-ethoxy-pregna-3,5-dien-20-one (green) by means of X-ray and NMR analysis.