Using CCOC(=O)C=Cc1c(OC)c(=O)[nH]c2cc(Cl)ccc2c1=O to produce CCOC(=O)/C=C/c1c(O)c(=O)[nH]c2cc(Cl)ccc2c1=O, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.