Carbohydrates thioglycosides

A central theme of carbohydrate chemistry today is the construction of oligosaccharides as they are found in glycoproteins (H. Paulsen, 1990). Three closely related methods have proven to be reliable in complex syntheses, namely the halide, imidate, and thioglycoside methods. 

Carbohydrate derivatives, in which one or more of the oxygen atoms bonded directly to the carbon skeleton have been replaced by sulfur, are termed thiosugars. The placement of the sulfur atom at the anomeric position constitutes a special case, because thioglycosides, alkyl, aryl and heterocyclic, occupy a very important place as versatile glycosyl donors in glycosidation methodology. Anomeric thiocarbonyl compounds, on the contrary, have been less explored, although their potential and scope is likely to be similar. 

Carbohydrate Libraries in Solution Using Thioglycosides From Multistep Synthesis to Programmable, One-Pot Synthesis... 

Thioglycosides were first introduced in glycosidation reactions by Ferrier in 1973 [31], who used the ethylthio group at the anomeric position. Subsequently, Hanessian [32] demonstrated the usefulness of the 2-pyridylthiol. Currently, the phenylthio and the ethylthio carbohydrate derivatives are the most commonly used glycosyl donors from this class of... 

S. Hanessian and Y. Guindon, Chemistry of the glycosidic linkage. Direct conversion of glycosides into 1-thioglycosides by use of [alkyl (or aryl)thio] trimethylsilanes, Carbohydr. Res. 86 C3 (1980). 

A. Hasegawa, H. Ohki, T. Nagahama, H. Ishida, and M. Kiso, A facile, large-scale preparation of the methyl 2-thioglycoside of W-acetylneuraminic acid, and its usefulness for the re-stereoselective synthesis of sialoglycosides, Carbohydr. Res. 212 211 (1991). 

Thioglycosides have been prepared on solid phase by glycosylation of thiols with various types of glycosyl donor. Carbohydrate-derived thioethers have been used either to link carbohydrates to thiol-functionalized supports [9,26,78,79] or as glycosyl donors for the preparation of glycosides on solid phase (see Section 16.3.3). 

Several neoglycoproteins have been used in studying the role of carbohydrate in the clearance of glycoproteins from the circulation. Derivatives of BSA to which the 1-thioglycosides of /3-D-galactopyra-... 

Anomeric center reactivity has been observed for the API lincomycin hydrochloride. Lincomycin HC1 contains a carbohydrate portion that undergoes thioglycoside hydrolysis at the carbohydrate anomeric center (Fig. 127) (177). 

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