Abstract
The stereoselective synthesis of α- and β-C-glycosides is one of the most challenging areas of research in the field of glycoside
chemistry. In this review, we summarize the various methods available for stereocontrolled
glycosylation and also discuss the predictive models available to explain the stereochemical
outcome of six- and five-membered-ring oxocarbenium ions with allyltrimethylsilane
nucleophile under Lewis acid conditions.
1 Introduction
2 Stereochemical Aspects during Glycoside Bond Formation in Pyranosides
2.1 Lewis Acid Mediated Nucleophilic Addition to Six-Membered-Ring Oxocarbenium Ions
2.2 Arylalane Addition to Anhydroglucose
2.3 Glucal Epoxide Method
2.4 Glycosyl Leaving Group Substitution Method
2.5 Glycosylation via Transition-Metal-Mediated Cross-Coupling
3 Stereochemical Aspects during Glycoside Bond Formation in Furanosides
3.1 Lewis Acid Mediated Nucleophilic Addition to Five-Membered-Ring Oxocarbenium
Ions
4 Summary and Conclusion
Key words
C-glycosylation - stereoelectronic control - transition state - oxocarbenium ion -
pyranosides - furanosides