Chemical Name : 17β-Hydroxy-17α-ethynylestr-4-en-3-one (as per EP); 17-hydroxy-19-nor-17α-pregn-4-en-20-yn-3-one (as per USP)

Smiles : O=C1CC[C@@]2([H])C(CC[C@]3([H])[C@]2([H])CC[C@@]4(C)[C@@]3([H])CC[C@@]4(O)C#C)=C1