Using CC(=O)N[C@@H](COC(C)(C)C)C(=O)N[C@@H](CC(=O)OC(C)(C)C)C(=O)N[C@@H](C)C(=O)O, O=C1CCC(=O)N1O to produce CC(=O)N[C@@H](COC(C)(C)C)C(=O)N[C@@H](CC(=O)OC(C)(C)C)C(=O)N[C@@H](C)C(=O)ON1C(=O)CCC1=O, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.