['C1CC2(CCO1)CNC2', 'N#CC1(C[SH](=O)=O)CCCC1', 'N#CC1CCCC1', 'CS(=O)(=O)N1CC2(CCOCC2)C1']
The Murcko scaffold (minmal number of connected rings) of <smiles></smiles> is O=S(=O)(CC1CCCC1)N1CC2(CCOCC2)C1.