Synthesis of 3-amino-3,4-dideoxysugars

Abstract

Sequential treatment of methyl 3,4-O-isopropylidene-β-L-erytho-pentopyranosidulose (1) with aqueous sodium hydroxide and phenylhydrazine results in elimination of acetone and formation of 2S-methoxy-tetrahydropyran-3,4-dione 4-phenylhydrazone (7) as the main product. Similarly, methyl 6S-deoxy-3,4-O-isopropylidene-α-L-lyxo-hexopyranosid-2-ulose (2) was converted into 2R-methoxy-6S-methyltetrahydropyran-3,4-dione 4-phenylhydrazone (8). The effect of base on the related uloside, methyl 6-deoxy-2,3-O-isopropylidene-α-L-lyxo-hexopyranosid-4-ulose (16), resulted in the formation of 3-hydroxy-2-methyl-4H-pyran-4-one (maltol)(17). Compounds (7) and (8) have been converted into, respectively, 3-amino-3,4-dideoxy-D-erythro-pentopyranose (22) and 3-amino-3,4,6-trideoxy-L-ribo-hexopyranose (25).