['CC=O', 'CC(C)(C)OCCN1CCNCC1', 'CC(C)(C)O', 'CCN1CCN(C(C)=O)CC1', 'CC(C)C', 'CC(=O)N1CCN(CCO)CC1', 'CCOC(C)(C)C', 'CC(=O)N1CCNCC1']
The Murcko scaffold (minmal number of connected rings) of <smiles></smiles> is C1CNCCN1.