A new synthesis of 2-acetamido-4-O-(2-acetamido-3,4,6-tri-O-acetyl-2-deoxy-.BETA.-D-glucopyranosyl)-1,3,6-tri-O-acetyl-2-deoxy-.ALPHA.-D-glucopyranose (chitobiose octaacetate).
作者:SHIGEYUKI OGURI、SETSUZO TEJIMA
DOI:10.1248/cpb.28.3184
日期:——
Condensation of 1, 6 : 2, 3-dianhydro-β-D-mannopyranose with 2-methyl-(3, 4, 6-tri-O-acetyl-1, 2-dideoxy-α-D-glucopyrano)-[2', 1' : 4, 5]-2-oxazoline (2) in the presence of a catalytic amount of anhydrous p-toluenesulfonic acid in boiling 1, 2-dichloroethane afforded crystalline 4-O-(2-acetamido-3, 4, 6-tri-O-acetyl-2-deoxy-β-D-glucopyranosyl)-1, 6 : 2, 3-dianhydro-β-D-mannopyranose (3) in 42% yield. Azidolysis of the oxirane ring of 3, reduction of the azido to an amino group, and N-acetylation afforded 2-acetamido-4-O-(2-acetamido-3, 4, 6-tri-O-acetyl-2-deoxy-β-D-glucopyranosyl)-3-O-acetyl-1, 6-anhydro-2-deoxy-β-D-glucopyranose (6) in 50% yield. Compound 6 was indistinguishable from the product prepared in 52.2% yield by direct condensation of 2-acetamido-3-O-acetyl-1, 6-anhydro-2-deoxy-β-D-glucopyranose with 2. Acetolysis of 6 provided the title disaccharide.
在沸点
1,2-二氯乙烷中,在催化量的无
水对甲苯磺酸存在下,1,6:2,3-二脱
水-β-
D-甘露糖与2-甲基-(3,4,6-三-O-乙酰基-1,2-二脱氧-α-
D-吡喃葡萄糖基)-[2',1':4,5]-2-
恶唑啉(2)缩合,得到结晶4-O-(2-乙酰
氨基-3,4,6-三-O-乙酰基-2-脱氧-β-
D-吡喃葡萄糖基)-1,6:2,3-二脱
水-β-
D-甘露糖(3),产率为42%。3的
环氧乙烷环的
叠氮化,
叠氮基还原为
氨基,N-乙酰化,得到2-乙酰
氨基-4-O-(2-乙酰
氨基-3,4,6-三-O-乙酰基-2-脱氧-β-
D-吡喃葡萄糖基)-3-O-乙酰基-1,6-脱
水-2-脱氧-β-
D-吡喃葡萄糖(6),产率为50%。化合物6与2-乙酰
氨基-3-O-乙酰基-1,6