['CC(=O)O', 'Cc1cn(-c2ccccc2)nc1-c1ccco1', 'c1ccccc1', 'O=C(O)/C=C/c1c[nH]nc1-c1ccco1', 'c1ccoc1', 'O=C(O)/C=C/c1cnn(-c2ccccc2)c1']
The Murcko scaffold (minmal number of connected rings) of <smiles></smiles> is c1ccc(-n2ccc(-c3ccco3)n2)cc1.