TWO METHYL ANHYDRO-D-FRUCTOPYRANOSIDES PREPARED FROM D-MANNITOL

Article abstract of DOI:10.1016/0008-6215(88)84027-8

D-Mannitol (1) was converted into 1,5-anhydro-D-mannitol, which was treated consecutively with p-toluenesulfonyl chloride (1 mol. equiv.) and benzoyl chloride (3 mol. equiv.), to produce 1,5-anhydro-2,3,4-tri-O-benzoyl-6-O-p-tolylsulfonyl-D-mannitol. 1,5-Anhydro-2,3,4-tri-O-benzoyl-6-deoxy-6-iodo-D-mannitol (4) was prepared by displacing the p-tolylsulfonyl group by reaction with sodium iodide. 1,5-Diazabicyclo(5.4.0)undec-5-ene eliminated hydrogene iodide from 4, to yield 1,5-anhydro-2,3,4-tri-O-benzoyl-6-deoxy-D-lyxo-hex-5-enitol (5).Addition of bromine in methanolic solution in 5 in the presence of potassium carbonate resulted in a separable mixture of methyl 1-bromo-1-deoxy-α-D-fructopyranoside (6) and methyl 1-bromo-1-deoxy-β-D-fructopyranoside (8).Dilute alkali converted 6 into methyl 1,3-anhydro-α-D-fructopyranoside, identify as its 4,5-diacetate.Dilute alkali converted 8 into methyl 1,4-anhydro-β-D-fructopyranoside.