Using CCCc1c(OCC(=O)OCC)ccc(C(C)=O)c1O, BrCCCCCBr to produce CCCc1c(OCC(=O)OCC)ccc(C(C)=O)c1OCCCCCBr, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.