Strategies for introducing sulfur atom in a sugar ring: synthesis of 5-thioaldopyranoses and their NMR data
Thiosugars containing a sulfur atom as heteroatom in the sugar ring are highly interesting. In particular, 5-thioaldopyranoses have attracted considerable attention because they exhibit biologically important properties as the substrates for glycosidases also can be developed as potential therapeutical agents, such as antineoplastic, anti-diabetic, antiviral, and antithrombotic agents. In this review, we describe and discuss the advances in synthetic strategies for the preparation of 5-thioaldopyranoses (5-thio-d-hexoses, 5-thio-l-hexoses, 5-thio-d-pentoses and 5-thio-l-pentoses), as well as their spectroscopic NMR data as known to date. The study aims to give readers an easy understanding of thiosugars chemistry and provide a useful guide for carbohydrate chemists.