['CCN', 'O=CN1[C@@H]2CCCC[C@@H]2C[C@H]1C(=O)O', 'CCNC=O', 'O=C(O)[C@@H]1C[C@H]2CCCC[C@H]2N1', 'CC', 'NC(=O)N1[C@@H]2CCCC[C@@H]2C[C@H]1C(=O)O', 'O=CO', 'CCNC(=O)N1CC[C@H]2CCCC[C@H]21']
The Murcko scaffold (minmal number of connected rings) of <smiles></smiles> is C1CC[C@H]2NCC[C@H]2C1.