Using COc1cn(CC(=O)OC(C)(C)C)c(=O)cc1-c1cc(Cl)ccc1C#N, CC1(C=O)COC1 to produce COc1cn(C(=CC2(C)COC2)C(=O)OC(C)(C)C)c(=O)cc1-c1cc(Cl)ccc1C#N, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.