Using COC(=O)c1ccc(/C=C(/C(=O)O)c2ccc(C(C)(C)C)cc2)s1 to produce COC(=O)c1ccc(CC(C(=O)O)c2ccc(C(C)(C)C)cc2)s1, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.