['CC(C)CCC=O', 'Nc1ccc(N2CCOCC2)nc1', 'C1COCCN1', 'CC(C)CCC(=O)Nc1cccnc1', 'CC(C)CCC(N)=O', 'c1ccc(N2CCOCC2)nc1']
The Murcko scaffold (minmal number of connected rings) of <smiles></smiles> is c1ccc(N2CCOCC2)nc1.