Using CCOc1c(S(C)(=O)=O)ccc(C(=O)C(C(=O)OC(C)(C)C)C(=O)C2CC2)c1C to produce CCOc1c(S(C)(=O)=O)ccc(C(=O)CC(=O)C2CC2)c1C, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.