['CC(C)(C)NCC=O', 'Cc1ccc(C)c(C(C)N)c1', 'CC(C)(C)NCC(N)=O', 'CCc1cc(C)ccc1C', 'CC(C)(C)N', 'CC(=O)NC(C)c1cc(C)ccc1C', 'CC(C)C', 'Cc1ccc(C)c(C(C)NC(=O)CN)c1', 'Cc1ccc(C)cc1', 'CCNC(=O)CNC(C)(C)C']
The Murcko scaffold (minmal number of connected rings) of <smiles></smiles> is c1ccccc1.