Acceptor Reactivity in the Total Synthesis of Alginate Fragments Containing α-<scp>L</scp>-Guluronic Acid and β-<scp>D</scp>-Mannuronic Acid
作者:Qingju Zhang、Erwin R. van Rijssel、Marthe T. C. Walvoort、Herman S. Overkleeft、Gijsbert A. van der Marel、Jeroen D. C. Codée
DOI:10.1002/anie.201502581
日期:2015.6.22
The total synthesis of mixed‐sequence alginate oligosaccharides, featuring both β‐D‐mannuronic acid (M) and α‐L‐guluronic acid (G), is reported for the first time. A set of GM, GMG, GMGM, GMGMG, GMGMGM, GMGMGMG, and GMGGMG alginates was assembled using GM building blocks, having a guluronic acid acceptor part and a mannuronic acid donor side to allow the fully stereoselective construction of the cis‐glycosidic
首次报道了以β- D-甘露糖醛酸(M)和α- L-古洛糖醛酸(G)为特征的混合序列藻酸盐寡糖的总合成。使用GM构件组装了一组GM,GMG,GMGM,GMGMG,GMGMGM,GMGMGMG和GMGGMG海藻酸盐,其具有古洛糖醛酸受体部分和甘露糖醛酸供体侧,以实现顺式的完全立体选择性构建糖苷键。发现还原端异头中心的性质与关键二糖受体中的反应性醇基团相距十个原子,这对构建单元的结合效率产生了巨大影响。这个手性中心决定了受体的整体形状,并且揭示了受体的构象柔韧性是决定糖基化反应结果的最重要因素。