Using O=C(O)COC12CC3CC(CC(C3)C1)C2, CC1(C)OC(=O)CC(=O)O1 to produce CC1(C)OC(=O)C(=C(O)COC23CC4CC(CC(C4)C2)C3)C(=O)O1, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.