(5-hydroxy-4-oxo-4H-pyran-2-yl)methyl 3-((((5-hydroxy-4-oxo-4H-pyran-2 yl)methoxy)carbonyl)amino)propanoate
(5-hydroxy-4-oxo-4h-pyran-2-yl)methyl 3-((((5-hydroxy-4-oxo-4h-pyran-2 yl)methoxy)carbonyl)amino)propanoate