Recent advances in stereoselective c-glycoside synthesis

The synthesis of 2-deoxyglycosides : 1988-1999

Glycals (or usually their O-substituted derivatives) are readily converted into 2,3-unsaturated glycosyl compounds with O-, C-, N-, S- or otherwise linked substituents at the anomeric position. These products have been found to be useful for a range of synthetic purposes. In particular, the C-glycosidic compounds have served as readily available starting materials for the preparation of useful non-carbohydrate compounds. While these allylic rearrangement processes are usually conducted under the influence of Lewis acid catalysts, adaptations that involve activation of the allylic substituents of the starting glycals as leaving groups under neutral conditions have been developed. General features of the reactions are described as well as applications in synthesis and extensions of the basic processes.

Substitution-with-Allylic-Rearrangement Reactions of Glycal Derivatives

Stereocontrolled glycosyl transfer reactions with unprotected glycosyl donors.

Recent advances in the synthesis of 2-deoxy-glycosides.

Practical and highly stereoselective aryl and allyl C-glycosidation methods using unprotected sugars as glycosyl donors have been developed. Aryl C-glycosidations of several unprotected 2-deoxy sugars with phenol and naphthol derivatives by the combined use of trimethylsilyl trifluoromethanesulfonate (TMSOTf)−AgClO4 or TMSOTf exclusively gave the corresponding unprotected o-hydroxyaryl β-C-glycosides which appear in many biologically attractive aryl C-glycoside antibiotics as the key subunit. On the other hand, allyl C-glycosidations of several unprotected glycals with allyltrimethylsilane by TMSOTf afforded the corresponding unprotected and 2,3-unsaturated allyl α-C-glycosides in high yields which are versatile synthetic intermediates for the syntheses of optically active natural products.

Aryl and Allyl C-Glycosidation Methods Using Unprotected Sugars

Novel glycosidations of glycals using BCl3 or BBr3 as a promoter for catalytic and stereoselective syntheses of 2-deoxy-α-glycosides

Environmentally benign aryl C-glycosidations of unprotected sugars using montmorillonite K-10 as a solid acid

Design, synthesis and biological evaluation of novel 1H-pyrazole-4-carbonyl-4,5,6,7-tetrahydrobenzo [b]thiophene derivatives as gut-selective NaPi2b inhibitors.

Aryl and Allyl C-Glycosidation Methods Using Unprotected Sugars.

Yasunobu Ushiki

Papers

Aryl and Allyl C-Glycosidation Methods Using Unprotected Sugars

Novel glycosidations of glycals using BCl3 or BBr3 as a promoter for catalytic and stereoselective syntheses of 2-deoxy-α-glycosides

Environmentally benign aryl C-glycosidations of unprotected sugars using montmorillonite K-10 as a solid acid

Design, synthesis and biological evaluation of novel 1H-pyrazole-4-carbonyl-4,5,6,7-tetrahydrobenzo [b]thiophene derivatives as gut-selective NaPi2b inhibitors.

Aryl and Allyl C-Glycosidation Methods Using Unprotected Sugars.