Showing papers on "Glucal published in 2010"
TL;DR: The conversion of cyclopropane-fused carbohydrates into oxepines is an attractive method for accessing diverse members of the septanoside family of carbohydrate mimetics, and 2-Bromooxepines are obtained through silver(I)-promoted thermal ring expansion of a d-glucal-derived gem-dihalocyclopropanated sugar.
Abstract: The conversion of cyclopropane-fused carbohydrates into oxepines is an attractive method for accessing diverse members of the septanoside family of carbohydrate mimetics. 2-Bromooxepines are obtained through silver(I)-promoted thermal ring expansion of a d-glucal-derived gem-dihalocyclopropanated sugar. In contrast, cyclopropane ring cleavage under basic conditions leads to 2-C-branched pyranosides, not the 2-bromooxepine structures assigned in an earlier report.
49 citations
TL;DR: A series of benzisothiazole- and indolizine-β-d-glucopyranoside inhibitors of human SGLT2 are described and the synthesis of the C-linked heterocyclic glucosides took advantage of a palladium-catalyzed cross-coupling reaction between a glucal boronate and the corresponding bromo heterocycle.
Abstract: A series of benzisothiazole- and indolizine-β-d-glucopyranoside inhibitors of human SGLT2 are described. The synthesis of the C-linked heterocyclic glucosides took advantage of a palladium-catalyzed cross-coupling reaction between a glucal boronate and the corresponding bromo heterocycle. The compounds have been evaluated for their human SGLT2 inhibition potential using cell-based functional transporter assays, and their structure−activity relationships have been described. Benzisothiazole-C-glucoside 16d was found to be an inhibitor of SGLT2 with an IC50 of 10 nM.
47 citations
TL;DR: In this paper, the Ferrier rearrangement of a selection of protected glycals was successfully performed using a commercially available H-USY zeolite CBV-720 as catalyst, selected after screening a range of similar catalysts.
34 citations
TL;DR: An improved method for the Ferrier sulfonamidoglycosylation of tri-O-acetyl-d-glucal with different N-nucleophiles has been developed in this article.
33 citations
TL;DR: The first stereoselective total synthesis of cryptopyranmoscatone B1 from 3,4,6-tri-O-acetyl-d -glucal was reported in this article.
33 citations
TL;DR: Novel one-pot three- and four-component transformations of D-glucal to furan-based hydroxy triazole glycoconjugates have been achieved by sequential addition of reagents in the presence of Cu(OTf)(2)-Cu powder as catalysts.
Abstract: Novel one-pot three- and four-component transformations of d-glucal to furan-based hydroxy triazole glycoconjugates have been achieved by sequential addition of reagents in the presence of Cu(OTf)2−Cu powder as catalysts. In general the carbohydrate-derived products were formed with high diastereomeric purity.
33 citations
TL;DR: Allenylsilanes are used as carbon nucleophiles in highly stereoselective Lewis acid-promoted C-glycosidations, resulting in the introduction of an internal alkyne with an adjacent stereocenter.
30 citations
TL;DR: The key step of the syntheses involves a highly stereoselective Lewis acid promoted coupling of 1,2-di-O-acyl-3,4,6-tribenzylglucose with tribenzylphloroglucinol, which gives rise to the corresponding beta-C-aryl glycoside in 30-65% yields.
26 citations
TL;DR: Based on chemo-enzymatic regio- and stereoselective reactions, new routes toward C-4 substituted N-acetyl- d -mannosamine (ManNAc) and the corresponding sialic acids from d -glucal were established.
24 citations
TL;DR: An efficient and convenient method for the synthesis of 2-deoxy-2-iodo- O-glycosides from tri-O-acetyl-D-glucal with various alcohols by using I₂-Cu(OAc)₁ is described.
16 citations
TL;DR: Molybdenum catalysts are efficient and selective catalysts for the tandem epoxidation/alcoholysis or epoxide/hydrolysis of glucal and galactal derivatives as mentioned in this paper.
Abstract: Molybdenum catalysts are efficient and selective catalysts for the tandem epoxidation/alcoholysis or epoxidation/hydrolysis of glucal and galactal derivatives. In glucal derivatives the selectivity is mainly controlled by the allylic substituent at position 3 of the glycal, obtaining in general the products derived from the initial formation of the α-epoxide (gluco) when this hydroxy group is protected, while products derived from the β-epoxide (manno) are mainly obtained when it is unprotected. In galactal derivatives the estereoselectivity is always high to give the α-epoxide (galacto) and independent of the protecting groups.
TL;DR: In this article, the observation of convertible formation between 2-deoxy-2-iodo-O-Glycosides and 2,3-unsaturated glycosides was described.
Abstract: The observation of convertible formation between 2-deoxy-2-iodo-O-glycosides and 2,3-unsaturated glycoside was described. The selective formation of 2-deoxy-2-iodo-O-glycosides was found from the reaction of D -glucal with iodine in the excess alcohol acceptor or the addition of ceric ammonium nitrate as additive while the addition of a stoichiometric amount of alcohol in solvent favored 2,3-unsaturated glycosides formation.
TL;DR: In this article, a short synthesis of 1-deoxy-l-gulonojirimycin from tri-O-benzyl-d-glucal, via a regioselective intramolecular cyclization of an amino triol intermediate, is described.
TL;DR: Gamma-aminobutyric acid analogs based on sugar scaffolds were prepared in six to nine steps starting from D-glucal and D-galactal starting from the Vilsmeier-Haack reaction that affords the corresponding GABA analog.
TL;DR: In this paper, the electrochemical bromination of 3,4,6-tri-O-acetyl-d -glucal has been investigated in DMSO by cyclic voltammetry and preparative-scale electrolyses.
TL;DR: In this article, β-enamino ketones were successfully synthesized by reaction of endo glycals with primary or secondary amines in the presence of hypervalent iodine reagent in one pot.
TL;DR: The reaction of benzyl alcohol with 3,4,6-tri-O-acetyl-d-glucal has been investigated with several heteropoly compounds and the optimal catalyst is 12-tungstophosphoric acid supported on carbon as mentioned in this paper.
TL;DR: The reaction of glucal (I) with alcohols affords 2,3-unsaturated glucopyranosides in high yield and α-selectivity as discussed by the authors, which is the same as the reaction of the reaction in this paper.
Abstract: The reaction of glucal (I) with alcohols affords 2,3-unsaturated glucopyranosides in high yield and α-selectivity.
TL;DR: In this paper, a stereoselective synthesis of (5 R, 6 R )- and (5 S, 6 S )-5-benzylamino-6-( tert -butyldimethylsilanyloxymethyl)-5,6-dihydropyran-2-ones starting from d -glucal and furanaldehyde, respectively, is described.
Abstract: Stereoselective synthesis of (5 R ,6 R )- and (5 S ,6 S )-5-benzylamino-6-( tert -butyldimethylsilanyloxymethyl)-5,6-dihydropyran-2-ones starting from d -glucal and furanaldehyde, respectively, is described. The synthesis relies on a Sharpless asymmetric dihydroxylation, an Achmatowicz reaction, and a stereoselective Pd-catalyzed allylic amination as the key steps.
TL;DR: In this article, the enantio-selectivesynthesis of (−)-(2 R,3 S,6 R)-decarestrictineL from commercially available tri-O-acetyl- D-glucal was described.
Abstract: We describe a new and efficient approach to the enantio-selectivesynthesis of (+)-(2 R,3 S,6 R)-decarestrictineL from commercially available tri- O-acetyl- D-glucal, based on a stereoselective Michaeladdition.
TL;DR: Michael-type addition of enamino esters to 3,4,6-tri-O-Obenzyl-2-nitro-D-glucal under solvent-free conditions formed C-glycosides in excellent yields with high stereoselectivity as discussed by the authors.
Abstract: Michael-type addition of enamino esters to 3,4,6-tri-O-benzyl-2-nitro-D-glucal under solvent-free conditions formed C-glycosides in excellent yields with high stereoselectivity. Reduction of the nitro group afforded the corresponding bicyclic 2-amino C-glycosides.
TL;DR: In this paper, the Mitsunobu reaction was used for the configuration inversion at C-6 by the sugar−non-sugar−sugar strategy, and the synthetic argentilactone has been tested against Leishmania mexicana.
Abstract: Starting from the commercially available d -glucal ( 2 ), the naturally occurring α,β-unsaturated δ-lactone argentilactone ( 1a ) has been synthesized. The important step is the configuration inversion at C-6 by the Mitsunobu reaction following the sugar–non-sugar–sugar strategy. The synthetic argentilactone has been tested against Leishmania mexicana for bioactivity.
TL;DR: In this paper, the first example of direct intermolecular conversion of a glycal to a mannosamine derivative is presented, which leads to a proposal for the generation of glucosamine derivatives from glycals and triazolinediones.
Abstract: Triazolinediones react with tri-O-acetyl-D-glucal to pro- vide the corresponding diazetidines as single stereoisomers possess- ing the mannosamine configuration at C2. The diazetidines undergo facile ring opening with alcohol and amine nucleophiles. While this methodology is not fully developed, it is the first example of direct intermolecular conversion of a glycal to a mannosamine derivative. Computational analysis provides mechanistic insight that in turn leads to a proposal for the generation of glucosamine derivatives from glycals and triazolinediones.
TL;DR: In the presence of catalytic amount of Pd(dba)2 and P(o-tol)3, the reaction of 3,4,6- tri -O- acetyl-2-bromo -d - glucal with ethylene proceeded smoothly to afford the conjugated dieno-pyranoside in high yield.
Abstract: In the presence of catalytic amount of Pd(dba)2 and P(o-tol)3, the reaction of 3,4,6- tri -O- acetyl-2-bromo - d - glucal with ethylene proceeded smoothly to afford the conjugated dieno-pyranoside in high yield. The Diels-Alder reaction of this carbohydrate-derived diene with some dienophiles constructed chiral carbocyclic system.
TL;DR: The reaction of benzyl alcohol with 3,4,6-tri-O-acetyl-d-glucal has been investigated with several heteropoly compounds and the optimal catalyst is 12-tungstophosphoric acid supported on carbon.
Abstract: The reaction of benzyl alcohol with 3,4,6-tri-O-acetyl-d-glucal has been investigated with several heteropoly compounds, and the optimal catalyst is 12-tungstophosphoric acid supported on carbon. In the presence of this catalyst, various alcohols gave the corresponding alkyl and aryl 2,3-unsaturated glycopyranosides in excellent yields and good anomeric selectivity under solvent-free condition. 4,6-Di-O-acetyl-2,3-dideoxy-α-d-erythro-hex-2-enopyranosyl cyanide and ethyl 4,6-di-O-acetyl-2,3-dideoxy-1-thio-α-d-erythro-hex-2-enopyranoside have also been prepared with trimethylsilyl cyanide and ethanthiol as nucleophiles, respectively. The catalyst could be easily recovered and reused several times with slight loss of activity. The selectivity to give α-anomers predominantly did not show any change in all runs.
TL;DR: Some N-substituted 3-azabicyclo[3.3.0] octen-7-one derivatives have been synthesized in an enantiomerically pure form starting from tri-O-acetyl-D-glucal via intramolecular Pauson-Khand (IPK) cycloaddition as discussed by the authors.
Abstract: Some N-substituted-3-azabicyclo[3.3.0]octen-7-one derivatives have been synthesized in an enantiomerically pure form starting from tri-O-acetyl-D-glucal via intramolecular Pauson-Khand (IPK) cycloaddition.
TL;DR: In this article, 2-Bromooxepines are obtained through the thermal ring expansion of a d-glucal-derived gem-dihalocyclopropanated sugar.
Abstract: The conversion of cyclopropane-fused carbohydrates into oxepines is an attractive method for accessing diverse members of the septanoside family of carbohydrate mimetics. 2-Bromooxepines are obtained through silver(I)-promoted thermal ring expansion of a d-glucal-derived gem-dihalocyclopropanated sugar. In contrast, cyclopropane ring cleavage under basic conditions leads to 2-C-branched pyranosides, not the 2-bromooxepine structures assigned in an earlier report.