['CN[C@@H]1COC[C@H]1O', 'CCC(C=O)N1CCCC1=O', 'O[C@H]1CCOC1', 'CCC(C(=O)NC)N1CCCC1=O', 'O=C1CCCN1', 'CCCC(=O)N(C)[C@@H]1COC[C@H]1O']
The Murcko scaffold (minmal number of connected rings) of <smiles></smiles> is O=C(CN1CCCC1=O)N[C@H]1CCOC1.