['CC(C)O', 'Cc1cc(=O)c2cc(C=O)ccc2[nH]1', 'CCC', 'Cc1cc(=O)c2cc(C(=O)O)ccc2[nH]1', 'CC(C)OC=O', 'Cc1cc(=O)c2ccccc2[nH]1']
The Murcko scaffold (minmal number of connected rings) of <smiles></smiles> is O=c1cc[nH]c2ccccc12.