3-((2R,3S,5R,6S)-6-(2,2-bis(phenylthio)ethyl)-5-((tert-butyldimethylsilyl)oxy)-3-((4-methoxybenzyl)oxy)tetrahydro-2H-pyran-2-yl)propanoic acid

(2R,4aR,6S,7R,8aS)-6-(2,2-bis(phenylthio)ethyl)-2-(4-methoxyphenyl)hexahydropyrano[3,2-d][1,3]dioxin-7-yl 3-((2R,3S,5R,6S)-6-(2,2-bis(phenylthio)ethyl)-5-hydroxy-3-((4-methoxybenzyl)oxy)tetrahydro-2H-pyran-2-yl)propanoate