['CN', 'CC(C)(C(=O)N1CC(C=O)C1)S(=O)(=O)C1CC1', 'CNC(=O)C1CNC1', 'CC(C)(C=O)S(=O)(=O)C1CC1', 'CNC=O', 'CC(C)(C(=O)N1CCC1)S(=O)(=O)C1CC1']
The Murcko scaffold (minmal number of connected rings) of <smiles></smiles> is O=C(CS(=O)(=O)C1CC1)N1CCC1.