['CO', 'Cc1ccc(N(CC=O)C(=O)CCl)cc1', 'O=CCCl', 'COC(=O)CNc1ccc(C)cc1', 'COC(C)=O', 'Cc1ccc(NC(=O)CCl)cc1', 'Cc1ccccc1', 'COC(=O)CNC(=O)CCl']
The Murcko scaffold (minmal number of connected rings) of <smiles></smiles> is c1ccccc1.