Using CC1(C)OC(=O)CC(=O)O1, CC(C)(C)OC(=O)NCCC(=O)O to produce CC(C)(C)OC(=O)NCCC(O)=C1C(=O)OC(C)(C)OC1=O, please predict the solvent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.