['CC', 'O=[N+]([O-])c1ccc(N2CCCC(O)C2)c2ncccc12', 'CCO', 'O=[N+]([O-])c1ccc(N2CCCCC2)c2ncccc12', 'CCOC1CCCNC1', 'O=[N+]([O-])c1cccc2ncccc12']
The Murcko scaffold (minmal number of connected rings) of <smiles></smiles> is c1cnc2c(N3CCCCC3)cccc2c1.