Preparation of linear oligosaccharides by a simple monoprotective chemo-enzymatic approach
作者:Marco Filice、Jose M. Palomo、Paolo Bonomi、Teodora Bavaro、Roberto Fernandez-Lafuente、Jose M. Guisan、Marco Terreni
DOI:10.1016/j.tet.2008.07.026
日期:2008.9
acetylated glycosyldonor, the glycosylation reaction with these glycosyl acceptors leads to peracetylated oligosaccharides. These compounds can be directly used as intermediates for the synthesis of glycopeptides used as antitumoral vaccines and, at the end of the process, can be easily fully deprotected in only one step. Thus, these key building blocks have been successfully used in glycosylation reactions
A simple one-pot azidochlorination for the preparation of nitrogen-containing Koenigs−Knorr glycosyl donors proceeds upon reaction of protected glycals with sodium azide, ferric chloride, and hydrogen peroxide. Different mono- and disaccharide galactals and glucals are converted in a highly α-selective manner to the 2-azido glycosyl chlorides. Starting from disaccharide galactals, building blocks for
A combined chemical and enzymatic strategy for the construction of carbohydrate-containing antigen core units
作者:Gary C. Look、Yoshitaka Ichikawa、Gwo Jenn Shen、Pi Wan Cheng、Chi Huey Wong
DOI:10.1021/jo00068a030
日期:1993.7
Glycosidase-mediated coupling of glycal acceptors with galactose donors affords beta1,3-linked disaccharides that are versatile intermediates for further chemical and enzymatic manipulation. The utility of these disaccharides is demonstrated by the elaboration of these compounds into the type I and type IV core disaccharides of carbohydrate-containing antigens. Further conversion of the type IV disaccharide to a mucin-type trisaccharide (Galbeta1,3(GlcNAcbeta1,6)GalNAc) was accomplished with the use of a beta1,6-N-acetylglucosaminyltransferase. This combined use of enzymatic and chemical methodologies allows for the rapid assembly, with high regio- and stereoselectivity, of core oligosaccharides of biologically important glycoconjugates.