['CC(C)C=O', 'CS(=O)(=O)N1CCN(CCN)CC1', 'CC(C)C(N)=O', 'CCN1CCN(S(C)(=O)=O)CC1', 'CCNC(=O)C(C)C', 'CS(=O)(=O)N1CCNCC1', 'C[SH](=O)=O', 'CC(C)C(=O)NCCN1CCNCC1']
The Murcko scaffold (minmal number of connected rings) of <smiles></smiles> is C1CNCCN1.