['CC(C)(C=O)C1CC1', 'CN1C[C@H]2CNC[C@H]2C1', 'C1CC1', 'CC(C)C(=O)N1C[C@H]2CN(C)C[C@H]2C1']
The Murcko scaffold (minmal number of connected rings) of <smiles></smiles> is O=C(CC1CC1)N1C[C@H]2CNC[C@H]2C1.