1-hydroxy Sugars Research Articles

A Mild and Environmentally Benign Synthetic Protocol for Catalytic Hydrolysis of Thioglycosides

A wide variety of thioglycosides 1 are selectively hydrolyzed to the corresponding 1-hydroxy sugars 2 in good yields at 0-5 °C, by employing V 2 O 5 -H 2 O 2 catalyzed oxidation of ammonium bromide in CH 2 Cl 2 -H 2 O solvent system. The methodology is very mild, environmentally benign, efficient and highly chemoselective. No side reactions such as bromination either at the anomeric position or double bond or oxidation at the sulfur are encountered.

Novel Dehydrative Glycosidations of 1-Hydroxy Sugars Using a Heteropoly Acid

Novel Dehydrative Glycosidations of 1-Hydroxy Sugars Using a Heteropoly Acid

Palladium(0)-Mediated Synthesis of Acetylated Unsaturated 1,4-Disaccharides

Alkylation of ethyl 6-O-tert-butyldiphenylsilyl-4-O-methoxycarbonyl-2,3-dideoxy-α-D-erythro-hex-2-enopyranoside (1) with various peracetylated 1-hydroxy sugars in the presence of a catalytic amount of palladium(O) gave the corresponding unsaturated 1,4-disaccharides and trisaccharides. In all cases the reaction is regio- and stereospecific according to the unsaturated moiety, alkylation occuring only at C-4 of the unsaturated carbohydrate, with overall retention of configuration.

A New Efficient Method for Catalytic Hydrolysis of Thioglycoside

Abstract A new and efficient method for catalytic hydrolysis of thioglycosides was successfully developed. Various thioglycosides were smoothly hydrolyzed to afford the corresponding 1-hydroxy sugars in high yields. The hydrolysis of disaccharides was took place smoothly without accompanying no anomerization of existing glycosidic bond.

Catalytic Stereoselective Synthesis of α-d-Galactopyranosides from 2,3,4,6-Tetra-O-benzyl-d-galactopyranose and Several Alcoholic Nucleophiles

Abstract The glycosylation reaction of several alcoholic nucleophiles with 2,3,4,6-tetra-O-benzyl-d-galactopyranose (1-hydroxy sugar) is successfully carried out by the combined use of Sn(OTf)2-Me3SiCl catalyst system and lithium perchlorate, an effective additive. Several α-d-galactopyranosides are obtained in good yields with high stereoselectivities.

Glycosidation with 1-Hydroxy Sugars as Glycosyl Donors Promoted by Trimethylsilyl Chloride and Zinc Triflate.

1-Hydroxy sugars (1a-4a) were directly coupled with free alcohols (5b-d) to give the corresponding glycosides by using trimethylsilyl chloride and zinc triflate as promoters.

An imrpoved practical method for synthesis of aryl C-glycosides from unprotected methyl glycosides and 1-hydroxy sugars

Aryl C-glycosidations of the unprotected methyl glycosides 9–12 and the unprotected 1-hydroxy sugars 14 and 15 with 2-naphthol 6 using TMSOTf proceed much more effectively than those of the acylated methyl glycosides 4 and 5; the unprotected methyl glycoside 10 is also smoothly coupled with other phenol and naphthol derivatives 25–27 to give the corresponding unprotected o-hydroxyaryl β-C-glycosides in high yields (TMSOTf = trimethylsilyloxytrifluoromethanesulfonate).

An Efficient Glycosylation Reaction of 1-Hydroxy Sugars with Various Nucleophiles Using A Catalytic Amount of Activator and Hexamethyldisiloxane

In the presence of hexamethyldisiloxane and anhydrous calcium sulfate, a catalytic amount of activator such as tin(II) trifluoromethanesulfonate, ytterbium trifluoromethanesulfonate , lanthanum trifluoromethanesulfonate or tin(II) chloride smoothly promotes the glycosylation reactions between 1-hydroxy sugars and free alcohols, electron-rich aromatic compounds or silylated nucleophiles to produce various O -, C - or N - glycosides stereoselectively in high yields. In the case of oxygen or nitrogen nucleophiles, β-ribosides are formed, except that α-ribosides are obtained predominantly in the presence of lithium perchlorate. In the case of carbon nucleophiles such as electron-rich aromatic compounds or silyl enol ethers derived from carbonyl compounds, perfect β-selectivity is shown either in the the presence or absence of lithium perchlorate. Further, pyranosyl substrates such as glucose or galactose afford the corresponding α-anomers, except with electron-rich aromatic compounds.

TMS triflate induced synthesis of 1,1'-disaccharides from 1-hydroxy sugars.

A variety of 1, 1'-disaccharides have been prepared by TMS triflate induced coupling of 1-hydroxy sugars in reasonable yield.

Catalytic O- and S-glycosylation of 1-hydroxy sugars

O-Protected 1-hydroxy sugars are effectively cross-coupled with a variety of alcohols and thiols to give the corresponding glycosides by using methoxyacetic acid and ytterbium(III) trifluoromethanesulfonate [Yb(OTf)3] as catalytic promoters.

A synthesis of aryl C-glycosides via polyketides

3,5,9,11-Tetraoxotridecanedioates containing C-glycoside units on the side chain were generated from 1-hydroxy sugars, β-ketoglutarate and acetoacetate; intramolecular condensation of the polyketide compounds gave C-glycosidic naphthalene-1,8-diols regio- and stereo-selectively.

Stereoselective Synthesis of 1,2-trans-Ribofuranosides from 1-Hydroxy Sugars by the Use of [1,2-Benzenediolato(2−)-O,O′]oxotitanium and Trifluoromethanesulfonic Anhydride

Abstract A convenient method for stereoselective synthesis of 1,2-trans-ribofuranosides directly from 1-hydroxy sugars and alcohols or trimethylsilylated nucleophiles by the use of [1,2-benzenediolato(2−)-O,O′]oxotitanium and trifluoromethanesulfonic anhydride is described.

Diphosphonium Salts as Effective Reagents for Stereoselective Synthesis of 1,2-cis-Ribofuranosides

Abstract 1,2-cis-Ribofuranosides are stereoselectively synthesized in high yields directly from 1-hydroxy sugars and alcohols or trimethylsilylated nucleophiles by the use of diphosphonium salts as a condensation reagent.

ChemInform Abstract: STEREOSELECTIVE SYNTHESIS OF α‐RIBONUCLEOSIDES FROM 1‐HYDROXY SUGARS BY USING 2‐FLUOROPYRIDINIUM TOSYLATE

Chemischer InformationsdienstVolume 15, Issue 41 Natural Products ChemInform Abstract: STEREOSELECTIVE SYNTHESIS OF α-RIBONUCLEOSIDES FROM 1-HYDROXY SUGARS BY USING 2-FLUOROPYRIDINIUM TOSYLATE T. MUKAIYAMA, T. MUKAIYAMASearch for more papers by this authorY. HASHIMOTO, Y. HASHIMOTOSearch for more papers by this authorY. HAYASHI, Y. HAYASHISearch for more papers by this authorS. SHODA, S. SHODASearch for more papers by this author T. MUKAIYAMA, T. MUKAIYAMASearch for more papers by this authorY. HASHIMOTO, Y. HASHIMOTOSearch for more papers by this authorY. HAYASHI, Y. HAYASHISearch for more papers by this authorS. SHODA, S. SHODASearch for more papers by this author First published: October 9, 1984 https://doi.org/10.1002/chin.198441327Read the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat No abstract is available for this article. Volume15, Issue41October 9, 1984 RelatedInformation

STEREOSELECTIVE SYNTHESIS OF α-RIBONUCLEOSIDES FROM 1-HYDROXY SUGARS BY USING 2-FLUOROPYRIDINIUM TOSYLATE

Abstract A novel method for the preparation of α-ribonucleosides was developed by the use of 2-fluoro-1-methylpyridinium tosylate as a condensing reagent. Various α-ribonucleosides were synthesized from 1-hydroxy sugars and trimethylsilylated nitrogen compounds, such as nucleoside bases and azide, in good yields under mild conditions.