Highly regio- and stereo-selective C-arylglycosylations of the protected free sugars 1–4, the unprotected methyl glycosides 6–9 and the unprotected free sugars 10 and 11 with 2-naphthol 5 are effectively realized by the combined use of TMSOTf–AgClO4(TMSOTf = trimethylsilyloxytrifluoromethanesulfonate) as a catalytic activator.
An imrpoved practical method for synthesis of aryl C-glycosides from unprotected methyl glycosides and 1-hydroxy sugars
作者:Kazunobu Toshima、Goh Matsuo、Masaya Nakata
DOI:10.1039/c39940000997
日期:——
Aryl C-glycosidations of the unprotected methyl glycosides 9–12 and the unprotected 1-hydroxy sugars 14 and 15 with 2-naphthol 6 using TMSOTf proceed much more effectively than those of the acylated methyl glycosides 4 and 5; the unprotected methyl glycoside 10 is also smoothly coupled with other phenol and naphthol derivatives 25–27 to give the corresponding unprotected o-hydroxyaryl β-C-glycosides
sulfamidate group has been achieved by selective reduction of sulfamidate ketimine groups. The efficient access to the structurally unique glycals allowed the subsequent divergent synthesis of various naturally occurring 3-amino-2,3,6-trideoxysugars. In addition, Lewis acid-promoted glycosylation of the glycals provided a simple solution for the stereoselective installation of O- and C-linked aglycons on
具有顺式稠合环状磺酰胺基团的 3,5-顺式-3- 氨基甘醇的合成已通过选择性还原磺酰胺基酮亚胺基团实现。有效获取结构独特的糖醛允许随后不同地合成各种天然存在的 3-amino-2,3,6-trideoxysugars。此外,Lewis 酸促进的糖基化为氨基糖支架上 O 和 C 连接的糖苷配基的立体选择性安装提供了一种简单的解决方案。
Artificial Anthraquinone–Carbohydrate Hybrids: Design, Synthesis, DNA Binding, and Cytotoxicity