intermediates, which were transformed into D-glycero-D-talo-oct-2-ulopyranosylonic acid (Ko), as well as 3-O- and 4-O-p-nitrobenzoyl-Ko derivatives. The exo-allyl orthoester derivative, methyl [5,7,8-tri-O-acetyl-4-O-(4-nitrobenzoyl)-2,3-O-[(1-exo-allyloxy)-ethylidene]-D-glycero-beta-D-talo-oct-2-ulopyranos]onate, prepared from the 4-O-pNBz-protected Ko derivative, was elaborated into the alpha-Ko allyl
将Kdo衍
生物的
乙二醇酯转化为2,3-
脱水中间体,然后将其转化为D-
甘油-D-talo-oct-2-ulyryranosylonic acid(Ko)以及3-O-和4-Op-
硝基苯甲酰基-Ko衍
生物。外
烯丙基原酸
酯衍
生物,
甲基[5,7,8-三-O-
乙酰基-4-O-(4-
硝基苯甲酰基)-2,3-O-[(1-外-
烯丙
氧基)-亚乙基] -D由4-O-pNBz保护的Ko衍
生物制备的-
甘油-β-D-talo-oct-2-ulopyranos] onate被精制为α-Ko
烯丙基
酮糖苷,即还原性二糖α-Kdop-(2- -> 4)-Ko和二糖α-Kdop-(2-> 4)-Kop-(2->
OAll)。相反,[4,5,7,8-四-O-
乙酰基-3-O-(4-
硝基苯甲酰基)-
甲基-D-
甘油-D-talo-2-辛基
吡喃糖基
溴化]
甲酸甲酯[
碳水化合物。Res。,244(1993)69-84],与Kdo受体偶联,得到二糖α-Kop-(2->