The oligosaccharides and glycoconjugates have become leads of drug discovery in the last decades due to their versatile biological functions. Because of the low hydrolytic and/or enzymatic stability of the O-glycosidic bond between aglycon and sugar moiety in the natural glycosides, their S-, N- or C-glycosyl analogues are frequently used as glycomimetics [1, 2].
The thio-click addition reactions  are widely used for the synthesis of sulfur containing glycomimetics . The hydrothiolation of exo-glycals allows the synthesis of novel types of glycosylmethyl-sulfide (Gly-CH2-SR) mimetics [5-8]. The synthesis of mimetics with β-mannosidic bond is rather challenging, but due to the peculiarities of the thio-click reaction, formation of β-D-mannosylmethyl-sulfide type glycomimetics from exo-mannals can be expected with high regio- and stereoselectivity.
The goal of our research was the synthesis of per-O-acylated exo-mannals (2) starting from mannose via anhydroaldose-tosylhydrazones according to procedures elaborated in our laboratory . The synthesis of analogous per-O-alkylated derivatives (2, 3) was carried out from pyranoid and furanoid mannonolactones using methylene transfer reagents. In this presentation the synthesis and the photoinduced thiol addition reactions of the above exo-mannals towards 4 and 5 will be reported (See Figure 1.)
The research was supported by the EU and co-financed by the European Regional Development Fund under the project GINOP-2.3.2-15-2016-00008.
- Asano, N.; Kobayashi, Y.; Steiner, A.; Stütz, A.; Wrodnigg, T.; Vauzeilles, B.; Urban, D.; Doisneau, G.; Beau, J.-M.; Wessel, H.P.; Lucas, S.D Glycomometics in Glycoscience: Chemistry and Chemical Biology, (second edition) Fraser-Read B. O.; Tatsuta K.; Thiem J. Eds: Springer 2008, pp. 1885.
- Ernst B.; Magnani J. L. Nat. Rev. Drug Discov. 2009, 8, 661.
- Denes F.; Pichowicz M.; Povie G.; Renaud P. Chem. Rev. 2014,114, 2587.
- Dondoni A.; Marra A. Chem. Soc. Rev., 2012, 41, 573.
- Gervay J.; Flaherty T. M.; Holmes D. Tetrahedron, 1997, 53, 16355.
- Lázár L.; Csávás M.; Hadházi Á.; Herczeg M.; Tóth M.; Somsák L.; Barna T.; Herczegh P.; Borbás A. Org. & Biomol. Chem. 2013, 11, 5339.
- József J.; Juhász L.; Illyés T. Z.; Csávás M.; Borbás A.; Somsák L. Carbohydr. Res. 2015, 413, 63.
- József, J.; Juhász, L.; Somsák, L. New. J. Chem. 2019, 43, 5670
- Tóth M.; Somsák L. J. Chem. Soc. Perkin Trans. I. 2001, 942.