['CO', 'CN(CC=O)CC(=O)N(C)C1CC1', 'CNC1CC1', 'COC(=O)CN(C)CC=O', 'COC(C)=O', 'CNCC(=O)N(C)C1CC1', 'CNCC(=O)OC', 'CC(=O)N(C)C1CC1', 'C1CC1', 'CNC(=O)CN(C)CC(=O)OC']
The Murcko scaffold (minmal number of connected rings) of <smiles></smiles> is C1CC1.