['C1COCCN1', 'C[C@H]1OCC[C@H]1NCC=O', 'C[C@H]1OCC[C@H]1N', 'CC(=O)N1CCOCC1', 'C[C@@H]1CCCO1', 'NCC(=O)N1CCOCC1']
The Murcko scaffold (minmal number of connected rings) of <smiles></smiles> is O=C(CN[C@@H]1CCOC1)N1CCOCC1.