['OCCO', 'COc1ccc2cc(C=O)c(C)nc2c1', 'CCO', 'COc1ccc2cc(C(=O)O)c(C)nc2c1', 'CO', 'Cc1nc2ccccc2cc1C(=O)OCCO', 'O=COCCO', 'COc1ccc2ccc(C)nc2c1']
The Murcko scaffold (minmal number of connected rings) of <smiles></smiles> is c1ccc2ncccc2c1.