SYNTHESES OF THE ANALOGUES AND THE KETOSIDE DERIVATIVES OF SIALIC ACID,KDO,AND KDN.

1.利用氨基型霍纳-威廷反应合成了具有重要生物学意义的内毒素末端基团3-脱氧-D-甘露-2-辛酸、3-脱氧-D-甘油-D-半乳糖-2-非磺酸和5-acetamido-3，5-dideoxy-D-glycero-D-galacto-2-nonulosonic酸(N-乙酰神经氨酸，NANA)。在此基础上，合成了3-脱氧-D-阿拉伯基-2-庚磺酸和3-脱氧-D-葡萄糖-2-辛酸等磺酸类似物。该方法的优点是选择试剂的氨基保护基团[如苄氧基羰基(CBZ)和叔丁氧基羰基(Boc)]。因此，我们可以选择所需的保护基团来保护原料的羟基。这一新开发的方法使用稳定的Horner-Witing试剂，将为大规模合成磺酸衍生物提供一条途径。利用上述知识，还合成了5-epi-kdN衍生物，用于合成C-5修饰的kdN类似物和N标记唾液酸(NaNA)。

1. The biologically important terminal units of lipopolysaccharides, 3-deoxy-D-manno-2-octulosonic acid (KDO), 3-deoxy-D-glycero-D-galacto-2-nonulosonic acid (KDN), and 5-acetamido-3,5-dideoxy-D-glycero-D-galacto-2-nonulosonic acid (N-acetylneuraminic acid, NANA) were synthesized by the use of amino type Horner-Witting reaction. On the basis of above knowledge, ulosonic acid analogues such as 3-deoxy-D-arabino-2-heptulosonic acid and 3-deoxy-D-gluco-2-octulosonic acid were also synthesized. Merit of this method is to select the amino protecting group [such as benzyloxycarbonyl (Cbz) and t-butoxycarbonyl (Boc) ] of witting reagent. As a result, we can select the protecting group, which is needed, for the protection of hydroxyl group of starting materials. This newly developed methods by the use of stable Horner-Witting reagent will provide a route to large scale synthesis of ulosonic acid derivatives.2. By the use of the above knowleges, 5-epi-KDN derivative was also synthesized for synthesizing C-5 modified analogs of KDN and ^<15>N -labeled sialic acid (NANA).