Syntheses of 4, 5-Di-O-bexzyl-2-deoxy-2-C-methyl L-lyxose and Methyl 4, 5-Di-O-bexzyl-2-deoxy-2-C-methyl-3-O-metkyl-L-lyxonate

The title compounds, which possess C -methyl groups at the α-position of carbonyl groups and vicinal hydroxyl groups with syn (three) relationship, were synthesized efficiently from known 3-decxy-1, 2- O -isopropylidene-3- C -methyl-α-D-allofuranose. The synthetic routes involve: 1) inversion of C -5 configuration of the starting sugar, 2) suitable protection of the 5, 6-diol, and 3) glycol cleavage of the 1, 2-diol to an aldehyde or direct oxidation of the diol to carboxylic acid.