aldehyde 1 with C9 stabilized phosphoranes 2 and 3 respectively. The “smaller” C19 sugar 13 was prepared from a C12 aldehyde 1 and C7 phosphorane 4. All reactions with phosphoranes were performed under high pressure (13 kbar). No reaction was observed under normal pressure even at high temperature (ca 140°C). The synthesis of C19 and C21 monosaccharides was accomplished also under normal pressure when phosphoranes
C 21
单糖前体11和12分别通过C 12醛1与C 9稳定的膦烷2和3的偶联而合成。在“较小” C 19糖13是从C中制备12醛1和C 7正膦4。与
磷烷的所有反应均在高压(13 kbar)下进行。即使在高温(约140℃)下,在常压下也未观察到反应。C 19和C的合成当
磷烷被更多的亲核性
膦酸酯替代时,在常压下也可以完成21种
单糖。然而,与高级糖烯酮11、12和13一起分离出部分消除的产物(M-
苄醇)。糖α-羟基醛(14)即使在13kbar的压力下也不会与C 9-膦烷反应,尽管与更短的类似物-C 7
磷烷15的反应是在常压下在沸腾的苯中进行的。