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The syntheses, characterization, redox properties of new selenium coronands and of copper(I) and copper(II) complexes of selenium coronands are reported. Molecular structures in the solid state have been determined by X-ray crystallography.

The heteroanalogues of methyl alpha-D-maltoside containing heteroatoms in the nonreducing ring and the interglycosidic linkages have been synthesized. Oligosaccharides with sulfur in the interglycosidic linkage are found to be resistant to hydrolysis by glycosidases. In this, the sulfur-in-the-ring analogue of a glycoside of N-acetyllactosamine is 200 times stable to hydrolysis by a galactosidase. 5-thio-alpha-L-fucose shows good inhibitory activity against alpha-L-fucosidase.

A study was made on the use of phenyl selenoglycosides as glycosyl donors and acceptors in glycosidation reactions. These versatile compounds can give the desired selectivity in glycosidation reactions. The compounds' capacity for selective activation and their inertness are valuable properties that can be employed in the field of synthetic oligosaccharide chemistry. The results indicated the viability of selective activation of glycosyl bromide donors over phenyl selenoglycoside acceptors through silver trifluoromethanesulfonate promotion.

Research has been conducted on D-glucosamine. The authors describe the convertion of this compound into peracetylated building blocks via the use of synthetic strategy based on chemoenzymatic oligosaccharide synthesis.

The 5-thioglucopyranosyl trichloroacetimidate is an effective glycosyl donor for synthesizing novel disaccharides. The disaccharides possess sugar with a sulfur in the ring and a chalcogen atom-incorporated interglycosidic linkage. The 4,5,-dithiomaltoside and 4-seleno-5'-thiomaltoside may function as glycosidase inhibitors.

A practical sequence is described for converting D-glucosamine into peracetylated Gal(β-1,4)GlcNTroc(β1-S)Ph and Neu5Ac(α-2,3)Ga'l(β-1,4)GlcNTroc(β1-S)Ph building blocks using a synthetic strategy based on chemoenzymatic oligosaccharide synthesis. The known trichloroethoxycarbonyl, N-Troc, protecting group was selected as a suitable protecting group for both enzymatic and chemical reaction conditions. These oligosaccharide building blocks proved effective donors for the β-selective glycosylation of the unreactive OH-3 of a polymeric PEG-bound acceptor and for the axial OH-2 of a mannose acceptor in good yields. The resulting complex oligosaccharides are useful for vaccine and pharmaceutical applications. [ABSTRACT FROM AUTHOR]