4-Oxo-pentanoic acid (2R,3R,4S,5R,6R)-4,5-dihydroxy-6-hydroxymethyl-2-methoxy-tetrahydro-pyran-3-yl ester

4-Oxo-pentanoic acid (3aS,4R,6R,7R,7aS)-6-methoxy-4-(1-methoxy-1-methyl-ethoxymethyl)-2,2-dimethyl-tetrahydro-[1,3]dioxolo[4,5-c]pyran-7-yl ester