['CC(C)C=O', 'O=C1C=CC(=O)N1c1ccc(O)cc1', 'CC(C)C(=O)O', 'O=C1C=CC(=O)N1c1ccccc1', 'O=C1C=CC(=O)N1', 'CC(C)C(=O)Oc1ccccc1']
The Murcko scaffold (minmal number of connected rings) of <smiles></smiles> is O=C1C=CC(=O)N1c1ccccc1.