['CO', 'CC(C)OCCOCCC=O', 'CCC(=O)OC', 'CC(C)OCCO', 'CCOC(C)C', 'COC(=O)CCO', 'CC(C)O', 'CCOCCC(=O)OC', 'CCC', 'COC(=O)CCOCCO']
The Murcko scaffold (minmal number of connected rings) of <smiles></smiles> is None.