Using CN1C(=O)C2(COc3cc4c(cc32)OCCO4)c2c(C(=O)Oc3ccccc3)cccc21 to produce CN1C(=O)C2(COc3cc4c(cc32)OCCO4)c2c(C(=O)O)cccc21, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.