Using C1=COCCC1, O=c1[nH]c2c(OCc3ccccc3)ccc([C@@H](O)CBr)c2s1 to produce O=c1[nH]c2c(OCc3ccccc3)ccc([C@H](CBr)OC3CCCCO3)c2s1, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.