A nitro sugar derivative route to 2-thioepisophorose and 2-thiosophorose and their remarkable facile epimerization

✍ Scribed by Mária Petrušová; Erika Lattová; Mária Matulová; Ladislav Petruš; James N. BeMiller

• Book ID: 102994079
• Publisher: Elsevier Science
• Year: 1996
• Tongue: English
• Weight: 552 KB
• Volume: 283
• Category: Article
• ISSN: 0008-6215
• DOI: 10.1016/0008-6215(95)00395-9

✦ Synopsis

The addition of 1-thio-D-glucose sodium salt to per-O-acetylated 1,2-dideoxy-1-nitro-D-arabino-hex-1-enitol, readily available from D-arabinose, afforded the corresponding 2-S-glycosylated 1-deoxy-1-nitro-D-mannitol and -D-glucitol peracetates. These, after deacetylation, were transformed by the Nef reaction to 2-thioepisophorose and 2-thiosophorose, respectively. The 2-thiodisaccharides easily epimerize in aqueous sodium bicarbonate at ambient temperature to a 1:4 equilibrium mixture. The predominant 2-thiosophorose was obtained crystalline. A 1H NMR study of the epimerization in deuterium oxide showed that the reaction involves an H-2 proton exchange mechanism.