Journal ArticleDOI
Aryl and Allyl C-Glycosidation Methods Using Unprotected Sugars
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TLDR
In this paper, aryl and allyl C-glycosidation methods using unprotected sugars as glycosyl donors have been developed, which are versatile synthetic intermediates for the syntheses of optically active natural products.Abstract:
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.read more
Citations
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Book ChapterDOI
Substitution-with-Allylic-Rearrangement Reactions of Glycal Derivatives
TL;DR: 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 as discussed by the authors.
Journal ArticleDOI
Stereocontrolled glycosyl transfer reactions with unprotected glycosyl donors.
Stephen Hanessian,Boliang Lou +1 more
Book ChapterDOI
Synthesis and reactions of unsaturated sugars.
Robert J. Ferrier,John O. Hoberg +1 more
TL;DR: This chapter surveys the chemistry of most of the important types of monosaccharide derivatives that contain single alkene groups—notably, the glycols that are extremely valuable starting materials for a vast range of synthetic transformations.
Journal ArticleDOI
Novel glycosylation methods and their application to natural products synthesis.
TL;DR: In this short review article, several glycosylation methods that were developed in the authors' laboratories, including stereocontrolled gly cosylation using 2,6-anhydro-2, 6-dideoxy-2-6-dithio sugars for obtaining 2,7- dideoxy glycosides, C-glycosylations employing unprotected sugars, environmentally benign glycosYLation utilizing heterogeneous solid acids and ionic liquids, are recounted.
Journal ArticleDOI
Chiral auxiliary based approach toward the synthesis of C-glycosylated amino acids.
TL;DR: C-glycosylated amino acids can be obtained by a 1,3-dipolar cycloaddition of a chiral glycine equivalent and C-1 allyl- or vinyl-derived carbohydrate building blocks as the key step and are formed regio- and diastereoselectively.
References
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Journal ArticleDOI
Recent progress in O-glycosylation methods and its application to natural products synthesis
Kazunobu Toshima,Kuniaki Tatsuta +1 more
Journal ArticleDOI
Highly stereoselective approaches to .alpha.- and .beta.-C-glycopyranosides
Journal ArticleDOI
New approach to C-aryl glycosides starting from phenol and glycosyl fluoride. Lewis acid-catalyzed rearrangement of O-glycoside to C-glycoside
TL;DR: In this paper, Cp 2 HfCl 2 -AgClO 4 is particularly effective for this conversion, which leads to initial O-glycoside formation followed by rearrangement to C-congener.
Journal ArticleDOI
Pluramycins. old drugs having modern friends in structural biology
Journal ArticleDOI
Glycosyl Phosphites as Glycosylation Reagents: Scope and Mechanism
Hirosato Kondo,Shin Aoki,Yoshitaka Ichikawa,Randall L. Halcomb,Randall L. Halcomb,Helena Ritzen,Chi-Huey Wong +6 more
TL;DR: Mechanistic investigations of the reactions indicate that the glycosyl phosphite is activated by either TfOH or TMSOTf, depending on how the substrates are mixed.