A convenient synthesis of 4-amino-4-deoxy-L-arabinose and its reduction product, 1,4-dideoxy-1,4-imino-L-arabinitol.
Methyl beta-D-xylopyranoside in a mixture of N,N-dimethylformamide and 2-methoxypropene containing a little hydrogen chloride gave preponderantly the 2,3-O-isopropylidene derivative, which was readily converted into its 4-trifluoromethanesulfonate. The facile displacement of the triflate group gave a 4-azido-4-deoxy-alpha-L-arabinopyranoside derivative, and this, on mild acid treatment, was hydrolyzed to the 2,3-diol, or under more vigorous conditions to 4-azido-4-deoxy-L-arabinose. Methyl 2,3-di-O-acetyl-4-azido-4-deoxy-alpha-L-arabinopyranoside, from the diol, appears (1H-n.m.r. data) to exist as an equilibrating mixture of the 4C1 and 1C4 conformers in chloroform solution. The reduction of the azido sugar by hydrogen over Pd/C in .6M HCl yielded 4-amino-4-deoxy-L-arabinopyranose as its hydrochloride; in 0.1M HCl, further reactions occurred to give 1,4-dideoxy-1,4-imino-L-arabinitol as the final product. The aminodeoxypentose from lipid A precursor IIA, isolated from a Salmonella mutant by Raetz et al. in 1985, was shown to be identical with the synthetic aminoarabinose by t.l.c., 1H-n.m.r. spectroscopy, and g.l.c. of the acetylated reduction products.
Naleway
J J
JJ
Department of Biochemistry, College of Agricultural and Life Sciences, University of Wisconsin, Madison 53706.
Raetz
C R
CR
Anderson
L
L
D000606:Amino Sugars / Q000032:analysis / Q000138:chemical synthesis*; D001089:Arabinose; D002236:Carbohydrate Conformation; D055598:Chemical Phenomena; D002621:Chemistry; D002855:Chromatography, Thin Layer; D006017:Glycolipids / Q000032:analysis; D050113:Imino Furanoses; D008050:Lipid A / Q000031:analogs & derivatives / Q000032:analysis; D009682:Magnetic Resonance Spectroscopy; D015394:Molecular Structure; D010084:Oxidation-Reduction; D012486:Salmonella typhimurium / Q000032:analysis; D013402:Sugar Alcohols / Q000138:chemical synthesis*
D000606:Amino Sugars; D006017:Glycolipids; D050113:Imino Furanoses; D008050:Lipid A; D013402:Sugar Alcohols; C040142:lipid A precursors, bacterial; C058137:1,4-dideoxy-1,4-iminoarabinitol; C040134:4-amino-4-deoxyarabinose; D001089:Arabinose