Naleway J J, Raetz C R, Anderson L
Department of Biochemistry, College of Agricultural and Life Sciences, University of Wisconsin, Madison 53706.
Carbohydr Res. 1988 Aug 15;179:199-209. doi: 10.1016/0008-6215(88)84118-1.
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.
在含有少量氯化氢的N，N - 二甲基甲酰胺和2 - 甲氧基丙烯的混合物中，β - D - 吡喃木糖苷主要生成2,3 - O - 异亚丙基衍生物，该衍生物可容易地转化为其4 - 三氟甲磺酸酯。三氟甲磺酸酯基团的容易取代得到4 - 叠氮基 - 4 - 脱氧 - α - L - 阿拉伯吡喃糖苷衍生物，在温和的酸处理下，该衍生物水解为2,3 - 二醇，或在更剧烈的条件下水解为4 - 叠氮基 - 4 - 脱氧 - L - 阿拉伯糖。由二醇得到的甲基2,3 - 二 - O - 乙酰基 - 4 - 叠氮基 - 4 - 脱氧 - α - L - 阿拉伯吡喃糖苷，在氯仿溶液中似乎（1H - 核磁共振数据）以4C1和1C4构象异构体的平衡混合物形式存在。在0.6M HCl中，通过在Pd/C上用氢气还原叠氮糖得到4 - 氨基 - 4 - 脱氧 - L - 阿拉伯吡喃糖盐酸盐；在0.1M HCl中，发生进一步反应，最终产物为1,4 - 二脱氧 - 1,4 - 亚氨基 - L - 阿拉伯糖醇。1985年，Raetz等人从沙门氏菌突变体中分离出的脂质A前体IIA中的氨基脱氧戊糖，通过薄层层析、1H - 核磁共振光谱和乙酰化还原产物的气相色谱分析表明与合成的氨基阿拉伯糖相同。
