Using [Li]C, CC1(C)C2CCC3(C2)C1C(O)C(=O)CC3(C)C to produce CC1(O)CC(C)(C)C23CCC(C2)C(C)(C)C3C1O, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.