['CC1(C=O)CC1', 'CCS(=O)(=O)N1CCN[C@H](C)C1', 'CC[SH](=O)=O', 'C[C@@H]1CNCCN1C(=O)C1(C)CC1', 'CC1CC1', 'CCS(=O)(=O)N1CCN(C=O)[C@H](C)C1']
The Murcko scaffold (minmal number of connected rings) of <smiles></smiles> is O=C(C1CC1)N1CCNCC1.