Thioglycosides heterocyclic

Carbohydrate derivatives, in which one or more of the oxygen atoms bonded directly to the carbon skeleton have been replaced by sulfur, are termed thiosugars.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. 

Glycoside and nucleoside derivatives of 3-aniino-3-deoxy-4.-thio-DL-threofuranose have been synthesized starting from the thiane diol (H). Thus the 4-thioglycoside (15) was prepared from the heterocycle (16), itself obtained from (H) in seven steps, via a Pummerer rearrangement of the intermediate sulphoxide as shown in Scheme 9 Intramolecular cyclization of D-threose dithianes... 

---