['CC(C)CCC=O', 'CN(CCN)C1CC1', 'CCN(C)C1CC1', 'CC(C)CCC(N)=O', 'CNC1CC1', 'CCNC(=O)CCC(C)C', 'C1CC1', 'CNCCNC(=O)CCC(C)C']
The Murcko scaffold (minmal number of connected rings) of <smiles></smiles> is C1CC1.