Using CCC(=O)C(C(=O)OC(C)(C)C)C(=O)c1ccc(S(C)(=O)=O)cc1Cl to produce CCC(=O)CC(=O)c1ccc(S(C)(=O)=O)cc1Cl, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.