['CC(C)CCCN', 'Cc1cc(C(=O)NNC=O)c(C)o1', 'CCCC(C)C', 'Cc1cc(C(=O)NNC(N)=O)c(C)o1', 'Cc1ccc(C)o1', 'CC(C)CCCNC(=O)NNC=O']
The Murcko scaffold (minmal number of connected rings) of <smiles></smiles> is c1ccoc1.