Synthesis of novel analogues of the calicheamicin γ1 I and esperamicin A1B oligosaccharides
作者:Stéphane Moutel、Jacques Prandi
DOI:10.1039/b006113l
日期:——
respectively. Esperamicin A1B oligosaccharide analogue 5 is obtained after two deprotection steps of the fragment 24. After removal of the protecting groups of unit 23, the fully deprotected disulfide 33 is reduced and immediately coupled with the deprotected aromatic unit C 30 (or CD 31) to provide the calicheamicin γ1I oligosaccharide analogues 3 and 4. We also report the synthesis of hemiacetal 7 in which
的刺孢霉素三个类似物γ化学合成1我1和埃斯波霉素阿1B 2分中描述的寡糖,其中糖环E由碱性侧链E'取代。我们的合成策略始于ABE'片段的构建,该片段具有不寻常的βN–O糖苷键。硝酮20和适当的活化糖B 13或22的糖基化分别给出二糖23和24。在片段24的两个去保护步骤之后获得埃斯帕霉素A 1B寡糖类似物5。。去除单元的保护基团的后23时,完全去保护的二硫化33被降低,并立即与所述脱保护芳香单元C耦合30(或CD 31),以提供卡奇霉素γ 1我寡糖类似物3和4。我们还报告了半缩醛7的合成,其中CD和B环之间的硫酯功能被酯键取代。这arylsaccharide为新颖的合成所需要的关键中间体加利车霉素γ 1我类似物6。