Convergent stereoselective synthesis of multiple sulfated GlcNα(1,4)GlcAβ(1,4) dodecasaccharides
作者:Hiroshi Tanaka、Yusuke Tateno、Takashi Takahashi
DOI:10.1039/c2ob26928g
日期:——
In this paper, we describe an effective method for the elongation of a GlcNα(1,4)GlcAβ(1,4) sequence using a GlcNTrocα(1,4)GlcA disaccharide unit and the synthesis of the N- and/or O-sulfated GlcNα(1,4)GlcAβ(1,4) oligosaccharides. N-Troc protection of GlcNα(1,4)GlcA units was effective for the synthesis of the GlcNα(1,4)GlcAβ(1,4) oligosaccharides in comparison with the azido substituent. The GlcNα(1,4)GlcAβ(1,4) dodecasaccharide was successfully prepared by the direct β-selective glycosidation of glucuronate in the GlcNα(1,4)GlcAβ(1,4)GlcNα(1,4)GlcAβ(1,4) tetrasaccharide. In addition, the synthesis of the N- and/or O-sulfated GlcNα(1,4)GlcAβ(1,4) oligosaccharides was accomplished by fluorous-assisted deprotection and sulfation. The fluorous-assisted synthetic technology applied to the highly polar sulfated oligosaccharide permits it to be more easily separated from the highly polar reagents, such as SO3·NEt3.
本文介绍了一种利用 GlcNTrocδ±(1,4)GlcAδ²(1,4)二糖单元拉长 GlcNδ±(1,4)GlcAδ²(1,4)序列并合成 N-和/或 O-硫酸化 GlcNδ±(1,4)GlcAδ²(1,4)寡糖的有效方法。与叠氮取代基相比,GlcNδ±(1,4)GlcA 单元的 N-Troc 保护能有效合成 GlcNδ±(1,4)GlcAδ²(1,4) 低聚糖。通过对 GlcNδ(1,4)GlcAδ(1,4)四糖中的葡萄糖醛酸进行直接δ-选择性糖苷化,成功制备了 GlcNδ(1,4)GlcAδ(1,4)十二糖。此外,N-和/或 O-硫酸化 GlcNδ±(1,4)GlcAδ²(1,4)寡糖的合成是通过荧光辅助脱保护和硫酸化来完成的。将氟辅助合成技术应用于高极性硫酸化寡糖,可使其更容易从 SO3Â-NEt3 等高极性试剂中分离出来。