Using CC(=O)[C@@]1(O)CC[C@H]2[C@@H]3C=CC4=CC(=O)C5CC5[C@@]4(C)[C@@H]3CC[C@@]21C to produce CC(=O)[C@@]1(O)CC[C@H]2[C@@H]3CCC4=CC(=O)C5CC5[C@@]4(C)[C@@H]3CC[C@@]21C, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.