['CO', 'Cc1ccccc1N(CC=O)C(=O)CCl', 'O=CCCl', 'COC(=O)CNc1ccccc1C', 'COC(C)=O', 'Cc1ccccc1NC(=O)CCl', 'Cc1ccccc1', 'COC(=O)CNC(=O)CCl']
The Murcko scaffold (minmal number of connected rings) of <smiles></smiles> is c1ccccc1.