Using CC(=O)OC(C)=O, CCOC(=O)[C@H]1[C@H]2[C@@H]1[C@](NC(=O)OC(C)(C)C)(C(=O)OCC)C[C@@H]2O to produce CCOC(=O)[C@H]1[C@H]2[C@@H]1[C@](NC(=O)OC(C)(C)C)(C(=O)OCC)C[C@@H]2OC(C)=O, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.