['CCO', 'O=C[C@@H]1C[C@H]2CCCC[C@@H]2N1', 'CC', 'O=C(O)[C@@H]1C[C@H]2CCCC[C@@H]2N1', 'CCOC=O', 'C1CC[C@@H]2NCC[C@H]2C1']
The Murcko scaffold (minmal number of connected rings) of <smiles></smiles> is C1CC[C@@H]2NCC[C@H]2C1.