Using COC(=O)C(C(=O)OC)c1ccc2c(c1)C(=O)c1cc3ccccc3cc1C2=O to produce O=C(O)Cc1ccc2c(c1)C(=O)c1cc3ccccc3cc1C2=O, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.