['CO', 'Cc1nsc(N2CC3COCC(C2)O3)n1', 'COCc1ncsn1', 'C1NCC2COCC1O2', 'COC', 'c1nsc(N2CC3COCC(C2)O3)n1']
The Murcko scaffold (minmal number of connected rings) of <smiles></smiles> is c1nsc(N2CC3COCC(C2)O3)n1.