Using COC(C)(C)OC, O=C(c1ccc(Br)cc1)[C@H]1C[C@H]1C(=O)O to produce COC(=O)[C@@H]1C[C@@H]1C(=O)c1ccc(Br)cc1, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.