Using O=C1CCC(=O)N1Br, CC(=O)c1cc(C(C)(C)C)c2c(c1)C(C)(C)CO2 to produce CC(C)(C)c1cc(C(=O)CBr)cc2c1OCC2(C)C, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.