Using COCOc1cc(CCC(=O)c2c(OC)cc(OC)c(CCC(C)C)c2O)ccc1OC, COC(=O)CBr to produce COCOc1cc(CCC(=O)c2c(OC)cc(OC)c(CCC(C)C)c2OCC(=O)OC)ccc1OC, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.