Conversion of 2,6-anhydro-d-altrose and -mannose derivatives with 4-substituted phenyl thiols to prepare compounds with potential antithrombotic activity

Acetolysis of methyl 3,4-di-O-acetyl-2,6-anhydro-d-altropyranoside afforded a mixture containing, besides 1,3,4-tri-O-acetyl-2,6-anhydro-d-altropyranose, the (1R) and (1S) diastereomers of methyl 2,6-anhydro-d-altrose-tetraacetate. Treatment of this mixture with 4-cyanobenzenethiol in the presence of trimethylsilyl triflate resulted in a mixture containing the 3,4,5-tri-O-acetyl-2,6-anhydro-d-altrose bis(4-cyanophenyl) dithioacetal, the corresponding O-methyl S-aryl monothiohemiacetal diastereomers and the β-thiopyranoside, respectively. Acetolysis of methyl 3,4-di-O-acetyl-2,6-anhydro-d-mannopyranoside led to a mixture of the (1R) and (1S) diastereomers of methyl 2,6-anhydro-d-mannosetetraacetate, which was converted into the corresponding O-methyl S-aryl monothiohemiacetals. Treatment of 1,1,3,4,5-penta-O-acetyl-2,6-anhydro-aldehydo-d-altrose and -d-mannose with 4-cyano- and 4-nitrobenzenethiol, respectively, in the presence of trimethylsilyl triflate afforded the corresponding dithioacetal derivatives. All arylthio derivatives obtained after deacetylation were tested for their oral antithrombotic activity.