The Chemistry of C-Glycosides, Volume 13

Introduction. Organization of the book. Definition and nomenclature of C-Glycosides. O-Glycosides vs C-Glycosides: comparisons of physical properties, anomeric effects, H-bonding abilities, stabilities and conformations. Natural occurring C-Glycosides. C-Glycosides as stable pharmacophores. Further reading. References. Electrophilic Substitutions. Introduction. Anomeric activating groups and stereoselectivity. Cyanation reactions. Alkylation, allenylation, allylation and alkynation reactions. Arylation reactions. Reactions with enol ethers, silylenol ethers and enamines. Nitroalkylation reactions. Reactions with allylic ethers. Wittig reactions with lactols. Nucleophilic additions to sugar lactones followed by lactol reductions. Nucleophilic additions to sugars containing enones. Transition metal mediated carbon monoxide insertions. Reactions involving anomeric carbenes. Reactions involving exoanomeric methylenes. References. Nucleophilic Sugar Substitutions. Introduction. C1 lithiated anomeric carbanions by direct metal exchange. C1 lithiated anomeric carbanions by reduction. C1 carbanions stabilized by sulfones, sulfoxides, carboxyl and nitro groups. References. Transition Metal Mediated C-Glycosidations. Introduction. Direct coupling of glycals with aryl groups. Coupling of substituted glycals with aryl groups. Coupling of &pgr;-allyl complexes of glycals. Mechanistic considerations. References. Anomeric Radicals. Introduction. Sources of anomeric radicals and stereochemical consequences. Anomeric couplings with radical acceptors. Intramolecular radical reactions. References. Rearrangements and Cycloadditions. Introduction. Rearrangements by substituent cleavage and recombination. Electrocyclic rearrangements involving glycals. Rearrangements from the 2-hydroxyl group. Biomolecular cycloadditions. Manipulations of C-Glycosides. References. Sugar Ring Formations. Introduction. Wittig reactions of lactols followed by ring closures. Addition of Grignard and organozinc reagents to lactols. Cyclization of suitably substituted polyols. Rearrangements. Cycloadditions. Other methods for the formation of sugar rings. References. Syntheses of C-Di and Trisaccharides. Introduction. Syntheses reported in 1983. Syntheses reported in 1984. Syntheses reported in 1985. Syntheses reported in 1986. Syntheses reported in 1987. Syntheses reported in 1988. Syntheses reported in 1989. Syntheses reported in 1990. Syntheses reported in 1991. Syntheses reported in 1992. Syntheses reported in 1993. Syntheses reported in 1994. Trends of the future. References. Index.

In recent years C-glycoside chemistry has been one of the main topics in carbohydrate chemistry, not only because of the synthetic challenges posed, but also because C-glycosides have the potential to serve as carbohydrate analogues resistant to metabolic processes. Consequently, this class of compounds is currently receiving much interest as a potential source of therapeutic agents for clinical use. This book provides a broad coverage of the various synthetic methods available for the preparation of C-glycosides, and illustrates the interesting breadth of connections between carbohydrate chemistry and modern general synthetic organic chemistry by including topics such as transition-metal catalysis, radical chemistry, cycloaddition and rearrangement processes. In addition, in the final chapter of the book, the syntheses of C-di and trisaccharides reported through 1994 are reviewed. This well organised account of the synthetic chemistry in this field will prove to be very valuable to a wide range of researchers and advanced students, both as an introduction to the topic and for reference.

For organic chemists, medicinal chemists, graduate students and academic and industrial researchers.