['CC(C)O', 'Cn1[nH]c2c(cnc3ccc(C=O)cc32)c1=O', 'CCC', 'Cn1[nH]c2c(cnc3ccc(C(=O)O)cc32)c1=O', 'CC(C)OC=O', 'Cn1[nH]c2c(cnc3ccccc32)c1=O']
The Murcko scaffold (minmal number of connected rings) of <smiles></smiles> is O=c1[nH][nH]c2c1cnc1ccccc12.