['CC(C)C(=O)NCCN', 'COc1cc(C=O)cc(OC)c1C', 'CC(C)C=O', 'COc1cc(C(=O)NCCN)cc(OC)c1C', 'CO', 'COc1cc(C(=O)NCCNC(=O)C(C)C)ccc1C', 'CCNC(=O)C(C)C', 'COc1cc(C(N)=O)cc(OC)c1C', 'CC(C)C(N)=O', 'CCNC(=O)c1cc(OC)c(C)c(OC)c1', 'CC(C)C(=O)NCCNC=O', 'COc1cccc(OC)c1C']
The Murcko scaffold (minmal number of connected rings) of <smiles></smiles> is c1ccccc1.