Thioglycosides block syntheses

The synthesis is an excellent example of the use of thioglycosides as glycosyl donors in the block synthesis of complex oligosaccharides as well as the use of partial glycosylation of diols to achieve short paths to the target. 

These final model experiments indicate that thioglycosides may be used in the block synthesis of 1.2- cis- linked glycosides with DMTST as promoter. With unreactive acc.eptors it may be advisable to refrain from transforming the reaction into a halide-assisted one by adding halide ion to the mixture. When the acceptor reactivity is sufficiently high, however, the presence of halide ion may significantly improve the stereospecificity and the yield of the desired product. 

The stability of thioglycosides in combination with their easy activation makes them highly suitable as donors in most glycosylation strategies and technologies, e.g. in block synthesis as well as in techniques where the donor is manipulated before glycosylation and in solid phase synthesis. 

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