Using COc1ccc(CCC(=O)c2cccc(O)c2)cc1OC, CC(C)(C)OC(=O)CBr to produce COc1ccc(CCC(=O)c2cccc(OCC(=O)OC(C)(C)C)c2)cc1OC, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.