Using COCOC(COC(=O)C(C)(C)C)COC(=O)C(C)(C)C, CC(=O)OC(C)=O to produce CC(=O)OCOC(COC(=O)C(C)(C)C)COC(=O)C(C)(C)C, please predict the solvent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.