Using O=C(C=Cc1ccccc1)C(Cc1ccccc1)C(=O)C=Cc1ccccc1 to produce O=C(CCc1ccccc1)C(Cc1ccccc1)C(=O)CCc1ccccc1, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.