Microwave-induced, Montmorillonite K10-catalyzed Ferrier rearrangement of tri-O-acetyl-d-galactal: mild, eco-friendly, rapid glycosidation with allylic rearrangement
TL;DR: Montmorillonite K10 was found to catalyze, under microwave irradiation, rapid O-glycosidation of 3,4,6-tri-O-acetyl-d-galactal to afford exclusively the alkyl and aryl 2,3-dideoxy-dthreo-hex-2-enopyranosides with very high α-selectivity as mentioned in this paper.
About: This article is published in Tetrahedron Letters.The article was published on 2002-09-16. It has received 46 citations till now. The article focuses on the topics: Ferrier rearrangement & Ferrier carbocyclization.
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TL;DR: Gold(III)chloride in catalytic amounts activates 3,4,6-tri- O -acetyl-d -glucal, 3, 4, 6-tri O −acetyl -d -galactal, and 3.4,di-O -acetylon- l -rhamnal efficiently as discussed by the authors.
54 citations
TL;DR: It is indicated, that conjugation of genistein with certain sugars may render the interaction of derivatives with new molecular targets with new Molecular targets.
45 citations
TL;DR: Er(OTf)(3) is a useful catalyst for the Ferrier rearrangement furnishing high yields of O- and S-glycosides and the catalyst, which is also commercially available, can be recovered and reused.
44 citations
TL;DR: In this paper, the efficiency of microwave irradiation at low temperature for glycosylations was described, and the suitable donors in microwave supported synthesis of Lewis X oligosaccharide were very stable acetate derivatives.
44 citations
TL;DR: In this paper, the reaction of tri-O-acetyl-D-glucal with different nitrogen nucleophiles was effectively promoted by a catalytic amount of tris(pentafluorophenyl)borane for the first time in acetonitrile at room temperature to produce a variety of azapseudoglycals via Ferrier rearrangement.
43 citations
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968 citations
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12 Oct 1994
TL;DR: This chapter discusses the history and applications of the Anomeric Effect in Organic Synthesis, and some of the applications can be found in the literature on endoelectronic effects of the anomeric effect.
Abstract: Historical Aspects and Definitions Origin and Consequences of the Anomeric Effect Theoretical Studies of the Anomeric Effect Stereoelectronic Effects Associated with the Anomeric Effect Endo and Exo Anomeric Interactions The Enthalpic Anomeric Effect Second- and Lower-Row Anomeric Interactions The Reverse Anomeric Effect The Kinetic Anomeric Effect Applications of the Anomeric Effect in Organic Synthesis
238 citations
TL;DR: Tri-O-acetyl-D-glucal undergoes complete reaction with alcohols in benzene solution in the presence of boron trifluoride to give 4,6-di-OðOðAðEðDÞÞ −2,3-dideoxy-α-DÒÞ−EðE Þ−hex-hex-2-enopyranosyl as discussed by the authors, which can be used to prepare the known crystalline ethyl αglucoside easily and in greatly improved
Abstract: Tri-O-acetyl-D-glucal undergoes complete reaction with alcohols in benzene solution in the presence of boron trifluoride to give 4,6-di-O-acetyl-2,3-dideoxy-D-erythro-hex-2-enopyranosides. The α-anomers predominate (ca. 90%), and the method can be used to prepare the known crystalline ethyl α-glucoside easily and in greatly improved yield. Other alkyl glycosides have been prepared similarly, and the procedure has afforded means of obtaining the cholesteryl analogue and the disaccharide derivative 6-O-(4,6-di-O-acetyl-2,3-dideoxy-α-D-erythro-hex-2-enopyranosyl)-1,2:3,4-di-O-isopropylidene-α-D-galactopyranose. Tri-O-acetyl-D-glucal again gave the 2,3-unsaturated glycosides on treatment with acetals in the presence of boron trifluoride; no evidence was obtained for the formation of branched-chain products produced by additions to the double bond.
179 citations
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.
Abstract: 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.
146 citations