['O=CC[C@H]1CCOC1', 'CCNC1CCNC1=O', 'CC', 'O=C(C[C@H]1CCOC1)NC1CCNC1=O', 'O=C1CCCN1', 'CCNC(=O)C[C@H]1CCOC1', 'C1CCOC1', 'CCN(C(C)=O)C1CCNC1=O']
The Murcko scaffold (minmal number of connected rings) of <smiles></smiles> is O=C(C[C@H]1CCOC1)NC1CCNC1=O.