['CCC=O', 'COc1ccc(OC)c(CN)c1', 'CO', 'CCC(=O)NCc1ccccc1OC', 'CCC(=O)NCc1cccc(OC)c1', 'CCC(N)=O', 'COc1ccc(OC)c(C)c1', 'CCC(=O)NC', 'COc1ccc(OC)cc1']
The Murcko scaffold (minmal number of connected rings) of <smiles></smiles> is c1ccccc1.