['CO', 'CCc1nsc(N2CC3CC4CC3C2C4O)n1', 'COC(C)c1ncsn1', 'OC1C2CC3CNC1C3C2', 'CCOC', 'OC1C2CC3CN(c4ncns4)C1C3C2']
The Murcko scaffold (minmal number of connected rings) of <smiles></smiles> is c1nsc(N2CC3CC4CC3C2C4)n1.