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.
Citations
More filters
TL;DR: In this paper, a simple procedure for the synthesis of 2,3-unsaturated glycosides in acetonitrile and tetrahydropyranylation of alcohols and phenols in dichloromethane in the presence of 3,5-dinitrobenzoic acid is described.
6 citations
TL;DR: A green reaction condition has been developed for the synthesis of 2,3-unsaturated glycopyranosides by the Ferrier rearrangement of glycals using alcohols and thiols in 1-butyl-3-methylimidazolium trifluoromethanesulfonate ([BMIM]·OTf) in excellent yield as mentioned in this paper.
Abstract: A green reaction condition has been developed for the synthesis of 2,3-unsaturated glycopyranosides by the Ferrier rearrangement of glycals using alcohols and thiols in 1-butyl-3-methylimidazolium trifluoromethanesulfonate ([BMIM]·OTf) in excellent yield. [BMIM]·OTf has been applied as a task specific ionic liquid organo-catalyst. Operational simplicity, environmentally benign reaction condition, use of task specific ionic liquid, short reaction time, high yields are the notable features of this methodology.
6 citations
18 Jan 2013
TL;DR: In this article, the authors reviewed microwave heating for expeditious chemical syntheses and showed that solvent-free reactions or reactions in benign media are convenient to perform and have advantages over the conventional heating protocols.
Abstract: Microwave heating, a unique heating technique is reviewed for expeditious chemical syntheses. Specifically, the solvent-free reactions or reactions in benign media are convenient to perform and have advantages over the conventional heating protocols as summarized in the previous editions. A wide range of selective functional group transformations have been accomplished expeditiously and efficiently using a variety of supported reagents on mineral oxides as catalysts or in benign reaction media. Further scale-up developments on such themes will go a long way in realizing the sustainable goals in the chemical arena including the synthesis of nanomaterials and nano-catalysts. The major limitations for MW-assisted reactions can be overcome by translating batch microwave chemistry to continuous flow domain wherein conventionally heated and suitably equipped fluidic flow devices may help produce meaningful amounts of chemical products in a continuous mode. This is especially true for the use of magnetic nano catalysis in flow chemistry which has a great potential to grow in this sustainable endeavor as the nanoparticle-bound magnetic catalysts can be confined and at the same time agitated in a reactor by a rotating magnetic field, thus, avoiding potential problems of clogging membranes or filters that are commonly used as barriers for immobilized catalysts.
Keywords:
Microwave Irradiation;
Solvent-free reactions;
Aqueous Chemistry;
Nano-catalysts
4 citations
TL;DR: α-2,3-Unsaturated galactosides were synthesized by the initial activation of d-galactals with diethyl phosphorochloridite and the subsequent glycosyl addition via Ferrier rearrangement with various O-nucleophiles in the presence of AlCl3 to give the glycoside products with excellent α-stereoselectivity.
4 citations
References
More filters
968 citations
Book•
[...]
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