Using CC(C)(C)OC(=O)NCC(O)CN, O=C(O)C[C@H](CCCCNC(=O)OCc1ccccc1)NC(=O)OCc1ccccc1 to produce CC(C)(C)OC(=O)NCC(O)CNC(=O)C[C@H](CCCCNC(=O)OCc1ccccc1)NC(=O)OCc1ccccc1, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.