Using COC(=O)c1cccc(-c2ccc3ccc(-c4cccc(C(=O)OC)c4)cc3c2)c1 to produce O=C(O)c1cccc(-c2ccc3ccc(-c4cccc(C(=O)O)c4)cc3c2)c1, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.