['NC1[C@H]2COC[C@@H]12', 'O=CCS(=O)(=O)C1CCCC1', 'C1OC[C@H]2C[C@@H]12', 'NC(=O)CS(=O)(=O)C1CCCC1']
The Murcko scaffold (minmal number of connected rings) of <smiles></smiles> is O=C(CS(=O)(=O)C1CCCC1)NC1[C@H]2COC[C@@H]12.