)-4,6- dideoxy-alpha-D-mannopyranoside (4) gave the fully acetylated disaccharide 5, which was deacetylated yielding the methyl alpha-glycoside of title disaccharide. The disaccharide glycosyl donor required for the blockwise synthesis of the title tri- and the tetra-saccharide, 3-O-acetyl-4-(2,4-di-O-acetyl-3-deoxy-L-glycero-tetronamido)-4,6-d ideoxy-2-O- methyl-alpha-D-mannopyranosyl-(1-->2)-3-O-acetyl-4-
将甲基4-(3-脱氧-L-
甘油-四氢酰胺基)-4,6-二脱氧-2-O-甲基-α-D-甘露
吡喃糖苷乙酰化,并用二
氯甲基甲基醚-ZnCl2处理完全保护的甲基糖苷( DCMME-ZnCl2)试剂可生成3-O-乙酰基-4-(2,4-二-O-乙酰基-3-脱氧-L-
甘油-四氢酰胺基)-4,6-二脱氧-2-O-甲基-α -D-
甘露聚糖氰基
氯(3)。3与甲基3-O-乙酰基-4-(2,4-二-O-乙酰基-3-脱氧-L-
甘油-四氢酰胺基)-4,6-二脱氧-α-D-甘露
吡喃糖苷的缩合反应(4)完全乙酰化的二糖5,其被脱乙酰化,得到标题二糖的甲基α-糖苷。标题三糖和四糖3-O-乙酰基-4-(2,4-二-O-乙酰基-3-脱氧-L-
甘油-四氢酰胺基)的嵌段合成所需的二糖糖基供体4,6-d ideoxy-2-O-methyl-alpha-D-mannopyranosyl-(1-> 2)-3-O-acetyl-4-(2,