Using CS(=O)(=O)Cl, CCOC(=O)[C@@H]1CC(O)CN1C(C)=O to produce CCOC(=O)[C@@H]1CC(OS(C)(=O)=O)CN1C(C)=O, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.