Using O=C(C(=O)c1ccc2c(c1)OCO2)c1ccc2c(c1)OCO2 to produce O=C(C(=O)c1ccc(O)c(O)c1)c1ccc(O)c(O)c1, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.