Manabe Shino, Ito Yukishige
RIKEN, Synthetic Cellular Chemistry Laboratory, 2-1 Hirosawa, Wako, Saitama, 351-0198, Japan.
Chem Rec. 2014 Jun;14(3):502-15. doi: 10.1002/tcr.201402004. Epub 2014 Jun 10.
Pyranosides with 2,3-trans carbamate groups exhibit high 1,2-cis selectivity in glycosylation reactions. Using glycosyl donors with N-benzyl 2,3-trans carbamate groups, an anti-Helicobacter pylori oligosaccharide was synthesized in an efficient manner. Moreover, pyranosides with 2,3-trans carbamate groups readily undergo anomerization from the β to the α configuration under mild acidic conditions via endocyclic cleavage. Acyclic cations generated during the endocyclic cleavage reaction were captured using reduction and intramolecular Friedel-Crafts reaction. By exploiting this anomerization, multiply aligned 1,2-trans glycosyl bonds can be transformed to 1,2-cis glycosyl bonds in a single operation.
具有2,3-反式氨基甲酸酯基团的吡喃糖苷在糖基化反应中表现出高的1,2-顺式选择性。使用具有N-苄基2,3-反式氨基甲酸酯基团的糖基供体，高效合成了一种抗幽门螺杆菌寡糖。此外，具有2,3-反式氨基甲酸酯基团的吡喃糖苷在温和酸性条件下通过内环裂解容易从β构型异构化为α构型。内环裂解反应中产生的无环阳离子通过还原和分子内傅克反应捕获。通过利用这种异构化，多个排列的1,2-反式糖基键可以在一次操作中转化为1,2-顺式糖基键。
