Using O=C([O-])[O-], CC1=C[C@H](O)CC2(CCCC2)[C@H]1C(=O)O to produce COC(=O)[C@H]1C(C)=C[C@H](O)CC12CCCC2, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.