A novel, mild and site-selective hydrogenation of equatorial azides in diazido hexoses, achieved using Lindlar catalyst, is reported. Optimization studies on l-β-2,4-dideoxy-diazido rhamnoside revealed exclusive reduction of the equatorial azide while axially positioned azide groups remain untouched, affording the corresponding monoamino sugar in up to 87% yield. The methodology proved reliable across different diverse substitution patterns, consistently favoring equatorial over axial azide reduction while allowing for straightforward purification and scalability.

Marine polysaccharides, including β3-xylan and mixed-linkage xylan (MLX), play a central role in the ocean’s carbon cycle. Using an optimized xylose donor, automated glycan assembly enabled the synthe...

Marine polysaccharides, including β3-xylan and mixed-linkage xylan (MLX), play a central role in the ocean’s carbon cycle. Using an optimized xylose donor, automated glycan assembly enabled the synthe...

Partially acetylated carbohydrates are integral to several biological functions and serve as synthetic intermediates for accessing complex glycoconjug…

Herein, we report the first total synthesis of the tetrasaccharide repeating unit of the O-antigens from P. aeruginosa serotype 4 via a linear [((1+1)+1)+1] assembly strategy. The high efficiency and....

Glycosyl phosphosaccharides, a ubiquitous and crucial family of complex carbohydrates, widely occur in living organisms. Considering the importance in various physiological and pathophysiological proc...

Reported herein is the expansion of the cooperatively catalyzed Koenigs–Knorr glycosylation reaction, known as “the 4K reaction”. It has recently been discovered that thioglycosides can be activated i...

The stereodirecting effect of various distal benzoyl esters on the anomeric selectivity in galactopyranosylations was investigated. It was found that esters on O-6 of galactosyl donors of the phenyl thioglycoside type had a negligible influence on the anomeric selectivity. Instead, α-selective galactosylations were observed with 4-O-benzoyl, 3,4-di-O-benzoyl, and 4,6-di-O-benzoyl protected galactosyl donors, with the highly electron-withdrawing p-nitrobenzoyl (pNO2Bz) protecting group providing the most α-selective galactosylations. Furthermore, the α-selectivity was enhanced by replacing the thiophenyl aglycon functionality with the highly reactive cyclohexyl aglycon functionality. These findings enabled the successful synthesis of the biologically relevant α-d-Gal(1→4)Gal linkage. The obtained results do not suggest distal participation as a course for the observed anomeric selectivities.

Glycans are intrinsically flexible molecules that can adopt many conformations. These molecules often carry ionic functional groups that influence glycan’s conformational preferences, dynamics, and ag...

We report the synthesis of betulinic acid and echinocystic acid saponins featuring an unnatural analogue of the Lewis-X trisaccharide, in which the l-fucose residue is replaced by l-rhamnose. These t....

The acylation of hydroxy groups serves as one of the most employed protecting group strategies in carbohydrate chemistry. Here, we present a base-free, supramolecular assisted approach for the O-acyla...

The formation of 1,2-trans-glycosides taking advantage of neighboring group participation by stereodirecting esters at the 2-position of glycosyl donors is widely held to be a robust and reliable prot...