Chemical Name : 13-Ethyl-17-hydroxy-18,19-dinor-17α-pregna-4,6,15-trien-20-yn-3-one (as per EP)

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