Using O=C(O)[C@H]1CCC[C@H](C(=O)c2ccc(Br)cc2)C1, COC(C)(C)OC to produce COC(=O)C1CCCC(C(=O)c2ccc(Br)cc2)C1, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.