O,O-DIALKYLPHOSPHORO-THIOIC AND -DITHIOIC ACIDS AS FUNCTIONALISING REAGENTS OF MONOSACCHARIDES: SYNTHESIS OF 6-DIALKOXYPHOSHINYLTHIO)-α-D-GLUCOFURANOSES, AND A NEW ROUTE TO 5,6-EPISULPHIDES

Article abstract of DOI:10.1016/S0008-6215(00)85362-8

5,6-Anhydro-1,2,-O-isopropylidene-α-D-glucofuranose (1) reacts smoothly with O,O-dialkylphosphoro-thioic and -dithioic acids and with diarylphosphinothioic acids, to give 6-substituted phosphinylthio and phosphinothioylthio derivatives in high yields.The reaction of 1 with th anions of O,O-dialkylphosphoro-thioic and dithioic acids yields, quantitatively, the 5,6-episulphide with inversion of the configuraton at C-5.A mechanism for this reaction is proposed, which involves a pentacovalent phosphorus intermediate.