Using CCC1(O)CC(=O)c2c(O)c3c(c(O)c2C1C(=O)OC)C(=O)c1cccc(O)c1C3=O to produce CCc1cc(O)c2c(O)c3c(c(O)c2c1C(=O)OC)C(=O)c1cccc(O)c1C3=O, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.