['C=CCN', 'O=CN1CCC2(CC1)CCS(=O)(=O)CC2', 'C=CCNC=O', 'O=S1(=O)CCC2(CCNCC2)CC1', 'C=CC', 'NC(=O)N1CCC2(CC1)CCS(=O)(=O)CC2']
The Murcko scaffold (minmal number of connected rings) of <smiles></smiles> is O=S1(=O)CCC2(CCNCC2)CC1.