Using O=Cc1ccc(F)c(F)c1, COCC(=O)CC(=O)OCc1ccccc1 to produce COCC(=O)C(=Cc1ccc(F)c(F)c1)C(=O)OCc1ccccc1, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.