A nitro sugar derivative route to 2-thioepisophorose and 2-thiosophorose and their remarkable facile epimerization.
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.
Institute of Chemistry, Slovak Academy of Sciences, Bratislava.
M
M
Petrusová
E
E
Lattová
M
M
Matulová
L
L
Petrus
J N
JN
BeMiller
D002236:Carbohydrate Conformation; D002240:Carbohydrate Sequence; D004187:Disaccharides / Q000138:chemical synthesis*; D005947:Glucose / Q000031:analogs & derivatives / Q000378:metabolism; D009682:Magnetic Resonance Spectroscopy; D008968:Molecular Conformation; D008969:Molecular Sequence Data; D015394:Molecular Structure; D009574:Nitro Compounds / Q000138:chemical synthesis*
D004187:Disaccharides; D009574:Nitro Compounds; C086801:2-thiosophorose; C018399:1-thioglucose; D005947:Glucose