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Journal ArticleDOI

Direct preparation of 2-deoxy-d-glucopyranosides from glucals without ferrier rearrangement

TL;DR: In this paper, an efficient catalytic procedure for the preparation of 2-deoxyglucosides from glucals without allylic or Ferrier rearrangement using triphenylphosphine hydrobromide and a wide variety of hydroxylic nucleophiles is described.
Abstract: An efficient catalytic procedure for the preparation of 2-deoxyglucosides from glucals without allylic or Ferrier rearrangement using triphenylphosphine hydrobromide and a wide variety of hydroxylic nucleophiles is described
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Journal ArticleDOI
28 May 1993-Science
TL;DR: Repeating glycosidic linkages of oligosaccharides can be synthesized by solid-phase methods using glycals attached to a polystyrene copolymer with a silyl ether bond.
Abstract: Repeating glycosidic linkages of oligosaccharides can be synthesized by solid-phase methods. Glycals were attached to a polystyrene copolymer with a silyl ether bond and were activated to function as glycosyl donors with 3,3-dimethyldioxirane. Glycosidation was performed by reactions with a solution-based acceptor (itself a glycal). Excess acceptor and promoter were removed by rinsing after each coupling, and the desired oligosaccharides were then easily obtained from the polymer by the addition of tetra-n-butylammonium fluoride. By this method, glycosidations are stereospecific and interior deletions are avoided.

273 citations

Journal ArticleDOI
TL;DR: This Review covers classical approaches to deoxyglycoside synthesis, as well as more recently developed chemistry that aims to control the selectivity of the reaction through rational design of the promoter.
Abstract: Deoxy-sugars often play a critical role in modulating the potency of many bioactive natural products. Accordingly, there has been sustained interest in methods for their synthesis over the past several decades. The focus of much of this work has been on developing new glycosylation reactions that permit the mild and selective construction of deoxyglycosides. This Review covers classical approaches to deoxyglycoside synthesis, as well as more recently developed chemistry that aims to control the selectivity of the reaction through rational design of the promoter. Where relevant, the application of this chemistry to natural product synthesis will also be described.

194 citations

Journal ArticleDOI
TL;DR: All methods of catalytic glycosylation with the focus on the development and application in oligosaccharide synthesis and an overview of the scope and limitations of these are provided.
Abstract: Catalytic glycosylation has been a central reaction in carbohydrate chemistry since its introduction by Fischer 125 years ago, but it is only in the past three to four decades that catalytic methods for synthesizing oligosaccharides have appeared. Despite the development of numerous elegant and ingenious catalytic glycosylation methods, only a few are in general use. This review covers all methods of catalytic glycosylation with the focus on the development and application in oligosaccharide synthesis and provide an overview of the scope and limitations of these. The review also includes relevant mechanistic studies of catalytic glycosylations. The future of catalytic glycosylation chemistry is discussed, including specific, upcoming methods and possible directions for the field of research in general.

175 citations

Journal ArticleDOI
TL;DR: Photolysis of 0.25 equiv of W(CO)6 in the presence of tertiary amines and highly functionalized terminal alkynyl alcohols catalyzes single-step, high-yield cycloisomerization to endocyclic enol ethers, leading to enantio- and diastereoselective syntheses of each isomer of 6-deoxy-1,2-glycals.
Abstract: Photolysis of 0.25 equiv of W(CO)6 in the presence of tertiary amines (triethylamine or DABCO) and highly functionalized terminal alkynyl alcohols catalyzes single-step, high-yield cycloisomerization to endocyclic enol ethers. This transformation is general for each diastereomeric 3,4-bissilyl ether of 5-hydroxy-1-hexyne, leading to enantio- and diastereoselective syntheses of each isomer of 6-deoxy-1,2-glycals. Stereoselective glycosylations have also been demonstrated for each glycal diastereomer, and have been applied in the preparation of d-digitoxose-β-4-d-digitoxose glycal.

173 citations