Using [O-]Br, COc1cc(C(C)=O)c(OC)c2c1C(C)(C)CCC2(C)C to produce COc1cc(C(=O)O)c(OC)c2c1C(C)(C)CCC2(C)C, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.