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The aza analogue 3 of iso-levoglucosenone, which is easily accessible from furylglycine, was used as a flexible building block for the synthesis of various imino sugars. Enantiomerically pure products are available starting from optically active furylglycine derivatives. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)

The reactivity of a number of p-methylphenyl thioglycoside (STol) donors which are either fully protected or have one hydroxyl group exposed has been quantitatively determined by HPLC in conjunction with the development of a broadly applicable approach for a facile one-pot synthesis of oligosaccharides. The influence on reactivity of the structural effects of different monosaccharide cores and different protecting groups on each glycoside donor is characterized and quantified. In addition, a correlation between glycosyl donor reactivity and the chemical shift of the anomeric proton by 1 H NMR has been established. A database of thioglycosides as glycosyl donors has been created using this reactivity data. The utility is demonstrated by the easy and rapid one-pot assembly of various linear and branched oligosaccharide structures. In addition, a computer program as been described for use as a database search tool and guide for the selection of building blocks for the one-pot assembly of a desired oligosaccharide or a library of individual oligosaccharides.

A short and effective synthesis of N-linked di- and trisaccharides is described. In a high-yielding reaction sequence, the glucosamine derivative 1 was transformed to the 3-azido-2,3-dideoxy sugar ...

[reaction: see text] A concise synthesis of the amino acid (2S,4R)-4-hydroxyornithine is described. Starting from diprotected L-aspartic acid, the scaffold of the target compound is constructed in a three-step approach: an efficient alpha-nitroketone formation through acylation of nitromethane is followed by a diastereoselective reduction of the resulting ketone. In the last step, the nitro group is reduced to furnish the (2S,4R)-4-hydroxyornithine scaffold. This new approach to the title compound offers advantages to the synthetic pathways previously described.

m CPBA induced oxidative cyclization of the aminoalcohol 1a under complete stereocontrol, generating after acetal formation a new diastereomerically pure key intermediate 2b for the flexible synthesis of azasugars. 2b could be converted to protected rac -mannonojirimycin, 3 in only three steps.

A chemoenzymatic strategy has been developed for the synthesis of libraries of iminocyclitol derivatives for the discovery of new and selective fucosidase inhibitors.

A short and effective synthesis of N-linked di- and trisaccharides is described. In a high-yielding reaction sequence, the glucosamine derivative 1 was transformed to the 3-azido-2,3-dideoxy sugar ...

A chemoenzymatic strategy has been developed for the synthesis of libraries of iminocyclitol derivatives for the discovery of new and selective fucosidase inhibitors.

An efficient scalable synthesis of 2-halothiazolium-type peptide coupling reagents has been developed. The key step is the formation of the 2-bromothiazole scaffold through cyclization of α-thiocyanato ketones with hydrogen bromide. Using this method, the new coupling reagent 2-bromo-N-methylthiazolium bromide (BMTB) was synthesized. BMTB was tested in a difficult model coupling reaction of two sterically hindered N-methylated amino acids and showed higher activity than the well-established peptide coupling reagent HATU.