Using COC(=O)[C@H](C)O, Cc1sc2c(Sc3ccccc3)c3ccccc3c(-c3cc(Br)c(O)c(Br)c3)c2c1C to produce Cc1sc2c(Sc3ccccc3)c3ccccc3c(-c3cc(Br)c(O[C@H](C)C(=O)O)c(Br)c3)c2c1C, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.