Abstract
The first synthesis of the trisaccharide unit of versipelostatin, a down regulator
of grp78, was achieved, utilizing methyl triflate promoted glycosidations of thioethyl
glycosyl donors of d-digitoxose and d-cymarose with protected digitoxal. The synthesis was terminated by the preparation
of a thioglycoside based on diethyldithionophosphonic acid which is ready for further
glycosidations with aglycons. Comparison of NMR spectroscopic data of two trisaccharides
with the data reported for versipelostatin supported the configuration of the monosaccharide
units as well as glycosidic linkages.
Key words
antibiotics - deoxy sugars - glycols - glycosidations - glycoconjugates - thioglycosides
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