Using COc1cc(C)c(S(=O)(=O)N(C)CCOCC(=O)OC(C)(C)C)c(C)c1C to produce COc1cc(C)c(S(=O)(=O)N(C)CCOCC(=O)O)c(C)c1C, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.