['CC(C)C=O', 'CC(CN)(c1ccccc1)c1ccccc1', 'CC(C)C(N)=O', 'CC(C)(c1ccccc1)c1ccccc1', 'c1ccccc1', 'CC(C)C(=O)NCC(C)c1ccccc1']
The Murcko scaffold (minmal number of connected rings) of <smiles></smiles> is c1ccc(Cc2ccccc2)cc1.