Using CCOC(=O)c1cc(C23CC4CC(CC(C4)C2)C3)n[nH]1 to produce O=C(O)c1cc(C23CC4CC(CC(C4)C2)C3)n[nH]1, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.