The preparation of some potential intermediates for syntheses of aminopolydeoxy sugars related to antibiotics

Abstract

Starting from methyl 3,6-dideoxy-3-nitro-α-D-glucopyranoside (1) and proceeding through its 4-mesylate (2) and 2,4-dimesylate (3), respectively, methyl 3,4,6-trideoxy-3-nitro-α-D-xylo-hexopyranoside (4) and methyl 2-O-acetyl-3,4,6-trideoxy-3-nitro-α-D-threo-hex-3-enopyrano-side (5) were prepared. The 4,6-O-benzylidene derivatives (6, 8, and 10) of methyl 2-O-acetyl-3-deoxy-3-nitro-β-D-glucopyranoside, methyl 3-deoxy-3-nitro-α-D-glucopyranoside, and methyl 2,3-dideoxy-3-nitro-α-D-arabino-hexopyranoside were found to undergo without difficulty the Hanessian–Hullar reaction with N-bromosuccinimide, to give good yields of the corresponding 6-bromo-4-benzoates (7, 9, and 11). Partial anomerization giving the β-anomer 12 of 11 was observed under certain circumstances.