the conformational behaviors of 2,3-bis(methylthio)-1,4-dioxane (1), 2,3-bis(methylthio)-1,4-dithiane (2) and 2,3-bis(methylthio)-1,4-diselenane (3) have been analyzed by means ofhybrid-density functional theory (b3lyp/def2-tzvpp) based method and nbo interpretation.b3lyp/def2-tzvpp results showed that the axial conformations of compounds 1-3 are morestable than their equatorial conformations. ...

One of the most successful approaches in the synthesis of inhibitors of t he g lycosidases i s t he s ubstitution of t he e ndocyclic ox ygen i n monosaccharides by a nitrogen atom to get iminosugars. Given that many diseases h ave t heir o rigin i n t he malfunctioning of t hese e nzymes, t his glycomimetics bear s trong p otential a s dr ug c andidates. A t th eir p rotonated state, iminosuga...

Benzyl beta-D-galactofuranoside was efficiently obtained from 1,2,3,5,6-penta-O-benzoyl-alpha,beta-D-galactofuranose, via benzyl 2,3,5,6-tetra-O-benzoyl-beta-D-galactofuranoside. Conditions for the O-debenzylation were investigated in order to evaluate the synthetic application of the benzyl group as an anomeric protector of a galactofuranose moiety in synthetic strategies involving galactofura...

A new anomeric linker has been developed that facilitates the purification of glycans prepared by chemoenzymatic approaches and can readily give compounds that are appropriately modified for microarray development or glycan derivatives with a free reducing end that are needed as standards for the development of analytical protocols.

Resonances in the carbon-13 natural abundance, proton-decoupled, 90.5 MHz nuclear magnetic resonance spectrum of globotriaosylceramide were assigned to specific carbon nuclei. The chemical shifts were rationalized in terms of the number of sugar residues, the sugar ring structures, the positions and anomeric configurations of the intersugar linkages, and the approximate degree of unsaturation o...

[formula: see text] Conversion of the inexpensive L-arabinose 1 into the ethylthio ortho ester 7 followed by generation of the dialkoxyalkyl radical III produces the desired 2-deoxy-L-ribose triester 4 in excellent overall yield. It has been shown that the similar dialkoxyalkyl radical IV is not an intermediate in the 1,2-acyloxy shift of anomeric radical I.

Glycosyl thiols may be accessed from the corresponding reducing sugars in water without recourse to any sugar projecting groups by way of a DMC mediated reaction with thioacetic acid in the presence of base, and hydrolysis of the anomeric thioacetate. Glycosyl thiols produced by this method may be used to access glycoconjugates, such as glycopeptides by use of the thiol-ene click reaction.