['CC', 'O=C(O)[C@H]1CC(=O)N(CCO)C1', 'CCO', 'CCN1C[C@@H](C(=O)O)CC1=O', 'O=CO', 'CCOCCN1CCCC1=O', 'CCOCC', 'O=C1C[C@H](C(=O)O)CN1']
The Murcko scaffold (minmal number of connected rings) of <smiles></smiles> is O=C1CCCN1.