Using C=CCC1(C(=O)OC)CCc2cc(C(=O)OC)ccc2C1, CO to produce COC(=O)c1ccc2c(c1)CCC(CC=O)(C(=O)OC)C2, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.