Using COC(=O)[C@@H]1C[C@@H](OC(=O)N2Cc3cccc(Cl)c3C2)CN1, CC(C)(C)OC(=O)[C@H](C(=O)O)C(C)(C)C to produce COC(=O)[C@@H]1C[C@@H](OC(=O)N2Cc3cccc(Cl)c3C2)CN1C(=O)[C@@H](C(=O)OC(C)(C)C)C(C)(C)C, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.