17-oxo steroid 3-oxo Delta(4)-steroid exemestane 258494 6-methyleneandrosta-1,4-diene-3,17-dione 6-methylideneandrosta-1,4-diene-3,17-dione Androsta-1,4-diene-3,17-dione in which the hydrogens at position 6 are replaced by a double bond to a methylene group.a selective inhibitor of the aromatase (oestrogen synthase) system, it is used in the treatment of advanced breast cancer. C20H24O2 CHEBI:4953 ChemIDplus:107868-30-4 CiteXplore:10882163 DrugBank:DB00990 Exemestane InChI=1S/C20H24O2/c1-12-10-14-15-4-5-18(22)20(15,3)9-7-16(14)19(2)8-6-13(21)11-17(12)19/h6,8,11,14-16H,1,4-5,7,9-10H2,2-3H3/t14-,15-,16-,19+,20-/m0/s1 InChIKey=BFYIZQONLCFLEV-DAELLWKTSA-N KEGG COMPOUND:107868-30-4 KEGG COMPOUND:C08162 KEGG DRUG:D00963 Wikipedia:Exemestane [H][C@@]12CC(=C)C3=CC(=O)C=C[C@]3(C)[C@@]1([H])CC[C@]1(C)C(=O)CC[C@@]21[H] exemestane exemestano exemestanum