['C=CCN', 'CC(C)C(=O)Nc1ccccc1C=O', 'CC(C)C=O', 'C=CCNC(=O)c1ccccc1N', 'C=CC', 'CC(C)C(=O)Nc1ccccc1C(N)=O', 'CC(C)C(N)=O', 'C=CCNC(=O)c1ccccc1', 'C=CCNC=O', 'CC(C)C(=O)Nc1ccccc1']
The Murcko scaffold (minmal number of connected rings) of <smiles></smiles> is c1ccccc1.