['CC(C)(C)C=O', 'O=C(C1CCCNC1)N1CCCC1', 'C1CCNC1', 'CC(C)(C)C(=O)N1CCCC(C=O)C1', 'O=CN1CCCC1', 'CC(C)(C)C(=O)N1CCCCC1']
The Murcko scaffold (minmal number of connected rings) of <smiles></smiles> is O=C(C1CCCNC1)N1CCCC1.