In recent years, glycosyl thiols have become useful building blocks for the synthesis of certain glycoconjugates that may be considered to be analogues of glycopeptides and glycoproteins.1
Herein, we present a method that allows the direct conversion of reducing sugars to the corresponding glycoyl thiols. This method uses Lawesson’s reagent2 (LR) and was shown to be quite general and applicable for the preparation of a variety of differently protected and unprotected 1-thiosugars.
A one-pot method consisting of direct thionation followed by chemoselctive ligation was developed for site-selective protein glycosylation. This procedure, which uses LR, has been shown to be fully compatible with unprotected sugars, the products of wich can be used in our selenenylsulfide-mediated protein glycosylation stratergy.3