O,O-DIALKYLPHOSPHOROSELENOIC ACIDS AS FUNCTIONALISING REAGENTS OF MONOSACCHARIDES-III A NOVEL SYNTHESIS OF UNSATURATED SUGARS BY DEOXYGENATION OF SUGAR EPOXIDES WITH DIALKYLPHOSPHOROSELENOIC ACIDS

Article abstract of DOI:10.1016/S0040-4020(01)98912-4

Sugar epoxides are transformed in almost quantitative yields, under mild reaction conditions, into their corresponding unsaturated monosaccharides by reaction with O,O-dialkylphosphoroselenoic acids salts.A mechanism involving the formation of a penta-coordinate phosphorus intermediate is proposed. The deoxygenation was performed with the following sugar epoxides: 5,6-anhydro-1,2-O-isopropylidene-α-D-glucofuranose (1), 5,6-anhydro-1,2-O-cyclohexylidene-α-D-glucofuranose (2), methyl-2,3-anhydro-4,6-O-benzylidene-α-D-allopyranoside (3), methyl-2,3-anhydro-4,6-O-benzylidene-α-D-mannopyranoside (4) and 3,4,6-tri-O-acetyl-1,2-anhydro-α-D-glucopyranose (Brigl's anhydride) (5).