Chemical modification of maltose. V. A new synthesis of 2-acetamido-2-deoxy-4-O-.ALPHA.-D-glucopyranosyl-.ALPHA.-D-glucopyranose (N-acetylmaltosamine).
作者:MASAMI MORI、SETSUZO TEJIMA
DOI:10.1248/cpb.29.1893
日期:——
Crystalline 2', 3, 3', 4', 6'-penta-O-acetyl-1, 6-anhydro-β-N-acetylmaltosamine (10) was prepared in 7 steps from 1, 6 : 2, 3-di-anhydro-4-O-(4, 6-O-benzylidene-2-O-tosyl-α-D-glucopyranosyl)-β-D-mannopyranose (3) as follows : benzylation, azidolysis of the oxirane ring, detosylation, debenzylidenation, acetylation, reduction of the azido to an amino group with concomitant debenzylation, and acetylation. Acetolysis of the 1, 6-anhydro-β-ring of 3-O-acetyl-1, 6-anhydro-2-azido-2-deoxy-4-O-(2, 4, 6-tri-O-acetyl-3-O-benzyl-α-D-glucopyranosyl)-β-D-glucopyranose, which is the fifth intermediate in the synthesis of 10 from 3, yielded an anomeric mixture of the corresponding hexaacetates (12). Catalytic reduction of 12 followed by acetylation gave an anomeric mixture of 1, 2', 3, 3', 4', 6, 6'-hepta-O-acetyl-N-acetylmaltosamines (13). De-O-acetylation of 13 gave the title disaccharide 17. The mp and [α] D values of 17 were in fairly good agreement with those of N-acetylmaltosamine synthesized by Sinay et al. [M.A.M. Nassr, J.-C. Jacquinet, and P. Sinay, Carbohydr. Res., 77, 99 (1979)].
晶体 2',3,3',4',6'-五-O-乙酰基-1,6-脱
水-β-N-乙酰基
麦芽糖胺(10)由 1,6 : 2,3-二脱
水-4-O-(4,6-O-亚苄基-2-O-
对甲苯磺酸-α-
D-吡喃葡萄糖基)-β-D-
吡喃
甘露糖(3)经以下 7 个步骤制备而成:苄基化、
环氧乙烷环的
叠氮分解、去苄基化、去苄基化、乙酰化、将
叠氮基还原为
氨基并同时去苄基化和乙酰化。3-O-acetyl-1, 6-anhydro-2-azido-2-deoxy-4-O-(2, 4, 6-tri-O-acetyl-3-O-benzyl-α-D-glucopyranosyl)-β-D-glucopyranose 的 1, 6-anhydro-β- ring 的乙酰分解(这是由 3 合成 10 的第五个中间体)产生了相应六
乙酸酯的异构体混合物(12)。催化还原 12 并进行乙酰化,可得到 1、2'、3、3'、4'、6、6'-七-O-乙酰基-N-乙酰基
麦芽糖胺的异构体混合物(13)。对 13 进行去 O-乙酰化反应,得到标题二糖 17。17 的熔点和 [α] D 值与 Sinay 等人合成的 N-乙酰
麦芽糖胺的熔点和 [α]D 值相当吻合[M.A.M.Nassr、J.-C. Jacquinet 和 P. Sinay,Carbohydr. Res.,77,99(1979 年)]。