Crystallographic and spectroscopic study on a known orally active progestin

6,17a-dimethyl-4,6-pregnadiene-3,20-dione (medrogestone, 2) is for a long time known steroid endowed with progestational activity. In order to study its crystallographic and NMR spectroscopic properties with the aim to fill the literature gap, we prepared medrogestone following a traditional procedure. A careful NMR study allowed the complete assignement of the 1H and 13C NMR signals not only of medrogestone but also of its synthetic intermediates. The structural and stereochemical characterizations of medrogestone togheter with its precursor 17a-methyl-3-ethoxy-pregna-3,5- dien-20-one were described by means of X-ray analysis, allowing a deepened conformational investigation.