Using CC(C)(C)C(=O)OCBr, CCS(=O)C1=C(C(=O)[O-])N2C(=O)[C@@H](C(C)(C)O)[C@H]2S1 to produce CCS(=O)C1=C(C(=O)OCOC(=O)C(C)(C)C)N2C(=O)[C@@H](C(C)(C)O)[C@H]2S1, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.