2-Nitro Thioglycoside Donors: Versatile Precursors of β-d-Glycosides of Aminosugars
摘要:
2-Nitro thioglycosides can be prepared by the Michael addition of thiophenol to 2-nitroglycal derivatives. NIS/TMSOTf activation of these 2-nitro thioglycosides, in the presence of alcohols, rapidly and cleanly led to the desired glycosides in good yield and beta-selectivity. Reduction of the nitro group allowed generation of the corresponding 2-acetamido glycosides.
Synthesis of a thio-linked analogue of sialyl Lewis X
作者:Thomas Eisele、Alexander Toepfer、Gerhard Kretzschmar、Richard R. Schmidt
DOI:10.1016/0040-4039(96)00061-5
日期:1996.2
Thiolinked sialylLewisXanalogue 2 was obtained from neuraminic acid, D-galactose, and L-fucose. Galactose was transformed into 3-thiogalactose building block 6 and also into the required 3,4-dithioglucose moiety. Thioglycoside bond formation was performed via base-promoted S-glycosylation [Neu5Acα(2-3S)Gal and Galβ(1-4S)Glc linkages] and via acid catalyzed S-glycosylation [Fucα(1-3S)Glc and Glcβ-(1-1S)heptyl