Methyldienedione Synonyms: Estra-4,9-Diene-3,17-Dione CAS: 5173-46-6 MF: C18H22O2 MW: 270.37 Assay: 99% Character: White crystalline powder. Packing:Foil bag or as requirments Categories: Pharmaceutical Intermediates; Amino Acids; Intermediates & Fine Chemicals; Metabolites & Impurities; Pharmaceuticals; Steroids Usage: A potential metabolitie of STS 557 (Dienogest). A steroid with antiglucocorticoid activity.