SYNTHESIS OF DERIVATIVES OF 2,3-DIAMINO-2,3-DIDEOXY-D-GALACTOSE

Aminations of methyl 4,6-O-benzylidene-2,3-dideoxy-3-nitro-β-D-threo-hex-2-enopyranoside (2) with aqueous ammonia or, better, with a molten mixture of dry ammonium acetate and acetamide furnished methyl 4,6-O-benzylidene-2-N-benzylideneamino-2,3-dideoxy-3-nitro-β-D-galactopyranoside (4). In this reaction, one part of intermediate methyl 2-amino-4,6-O-benzylidene-2,3-dideoxy-3-nitro-β-D-galactopyranoside (3) evidently was N-benzylidenated by benzaldehyde lost from another part. Acetic anhydride converted 4 into methyl 2-acetamido-4,6-O-benzylidene-2,3-dideoxy-3-nitro-β-D-galactopyranoside (5) which by acidic de-O-benzylidenation yielded methyl 2-acetamido-2,3-dideoxy-3-nitro-β-D-galactopyranoside (6) (4,6-diacetate, 7). Catalytic hydrogenation of 6 followed by N-acetylation and N, O-acetylation, respectively, gave methyl 2-acetamido-3-amino-2,3-dideoxy-β-D-galactopyranoside hydrochloride (8), methyl 2,3-diacetamido-2,3-dideoxy-β-D-galactopyranoside (9), and methyl 2,3-diacetamido-4,6-di-O-acetyl-2,3-dideoxy-β-D-galactopyranoside (10). © 1969, American Chemical Society. All rights reserved.