['CNC1CCOC1', 'O=C[C@H]1CCCC(=O)N1', 'C1CCOC1', 'CNC(=O)[C@H]1CCCC(=O)N1', 'O=C1CCCCN1', 'CN(C=O)C1CCOC1']
The Murcko scaffold (minmal number of connected rings) of <smiles></smiles> is O=C1CCC[C@H](C(=O)NC2CCOC2)N1.