Showing papers on "Glucal published in 2015"
TL;DR: In this article, a general approach for the synthesis of 2-alkynyl-d-glucal derivatives has been achieved through a ligand and copper-free Sonogashira coupling.
30 citations
TL;DR: The biomimetic total synthesis of potential anti-HIV (−)-isatisine A, a novel alkaloid with an unprecedented fused tetracyclic skeleton, was accomplished in eight steps from indole and known 4,6- O -isopropylidene-protected glucal as discussed by the authors.
25 citations
TL;DR: A convergent total synthesis of 16-membered macrolactone natural product (−)-A26771B 1 starting from 3,4,6-tri-O-acetyl-D-glucal 7 is reported in this paper.
Abstract: A convergent total synthesis of a 16-membered macrolactone natural product (−)-A26771B 1 starting from 3,4,6-tri-O-acetyl-D-glucal 7 is reported. The Ferrier rearrangement of acetylated glucal 7, cross metathesis between chiral fragments 3 and 4, Yamaguchi macrolactonization and selective oxidation of the allylic alcohol are the key features of the synthesis.
20 citations
TL;DR: In this article, the synthesis of 2-deoxy-2-iodo-glycosylamides, glycosylurea, Nglycosylbenzotriazole, and N-glyco-imidazole by addition reaction of trimethylsilyl amides, imidazoles, and benzotitriazoles to D-glucal at 0 °C.
16 citations
TL;DR: A novel synthetic route leading to N-glycolyl muramyl dipeptide (MDP), a bacterial glycopeptide of particular interest in studies of nucleotide-binding oligomerization domain-containing protein 2 (NOD2), is described.
Abstract: A novel synthetic route leading to N-glycolyl muramyl dipeptide (MDP), a bacterial glycopeptide of particular interest in studies of nucleotide-binding oligomerization domain-containing protein 2 (NOD2), is described. The synthetic strategy hinges on the alkylation of benzylidene-protected glucal with 2-bromopropionic acid and thus circumvents a challenging and non-reproducible SN2 step at the C-3 position of glucosamine derivatives. The subsequent sequence includes an azidonitration and an unusual azide reduction/acylation step via an aza ylide/oxaphospholidine intermediate. This approach generates a protected N-glycolyl MDP that can be either subjected to a one-step global deprotection or differentially deprotected to obtain further derivatives.
13 citations
TL;DR: In this paper, an efficient Ferrier Rearrangement reaction system using Tm(OTf) 3 as the catalyst was established, and a series of O -, S -, N -, and C -2, 3-unsaturated-glucosides were obtained in good yields and high anomeric selectivities by the glycosidation of 3,4,6-tri-O -acetyl-d -glucal with the corresponding nucleophiles, including azaglycosylation with N -nucleophiles.
8 citations
TL;DR: An efficient, CuI-catalyzed, microwave-assisted method for the synthesis of bis-1,2,3-triazole derivatives starting from a 3,4,6-tri-$$O$$O-acetyl-d-glucal-derived mesylate with good yield is developed.
Abstract: We have developed an efficient, CuI-catalyzed, microwave-assisted method for the synthesis of bis-1,2,3-triazole derivatives starting from a 3,4,6-tri-O-acetyl-D-glucal-derived mesylate. This mesylate was obtained from 3,4,6-tri-O-acetyl-D-glucal through C-glycosidation, deprotection of acetate groups to alcohols, and selective mesylation of the primary alcohol. This mesylate moiety was then converted to an azide through a microwave-assisted method with good yield. The azide, once synthesized, was then treated with different terminal alkynes in the presence of CuI to synthesize various bis-triazoles in high yields and short reaction times.
7 citations
TL;DR: In this article, two strategies were considered for the synthesis of 2,3-unsaturated O-glucosyl-1,2, 3-triazoles using Ferrier rearrangement.
Abstract: Two strategies were considered for the synthesis of 2,3-unsaturated O-glucosyl-1,2,3-triazoles. The first, involving reaction between tri-O-acetyl- d -glucal and triazole alcohols gave no stereoselectivity. A second strategy provided 2,3-unsaturated O-glycosides from glycals and alkynols through a Ferrier rearrangement; this method, employing montmorillonite K-10 doped with iron(III) chloride hexahydrate in dichloromethane afforded new glycosides in good to excellent yields within short times and with high α-stereoselectivities. Subsequently, the glucosides were coupled with 2-azido-1,4-naphthoquinone to produce a new series of 1,2,3-1H-triazolyl O-glucoside derivatives through a click reaction.
7 citations
TL;DR: An efficient and concise method for the construction of various O-glycosidic bonds by a palladium-catalyzed reaction with a 3-O-picoloyl glucal was developed in this paper.
Abstract: An efficient and concise method for the construction of various O-glycosidic bonds by a palladium-catalyzed reaction with a 3-O-picoloyl glucal is developed.
7 citations
TL;DR: The same procedure proved to be appropriate in synthesizing dihydropyran derivatives ('C-glycosides') using allyltrimethylsilane as the nucleophile (only 'α-anomers' were obtained). All new compounds were fully characterized by spectral data, whereas single-crystal X-ray analysis was performed for two thioglycosides.
7 citations
TL;DR: In this paper, Dinemasones B and C were isolated from a culture of the endophytic fungus Dinemasporium strigosum and had shown attractive antimicrobial activities in vitro.
TL;DR: In this paper, N-alkylated tetrahydropyrano[3,2-c ]quinolines were synthesized via intramolecular Friedel-Crafts alkylation using a 1- O -acetylglucosyl derivative as the key intermediate.
Abstract: Diastereoselective synthesis of novel and enantiopure N-alkylated tetrahydropyrano[3,2- c ]quinolines is described via intramolecular Friedel–Crafts alkylation using a 1- O -acetylglucosyl derivative as the key intermediate. Unprecedented formation of new glycal derivatives and α,β-unsaturated carbaldehyde products is also discussed.
TL;DR: In this article, various O-glycosides are stereoselectively formed trough Pd-catalyzed tandem decarboxylation, proton abstraction, and nucleophilic addition.
Abstract: Starting from glucal derived carbonate (I), various O-glycosides are stereoselectively formed trough Pd-catalyzed tandem decarboxylation, proton abstraction, and nucleophilic addition.
TL;DR: In this article, a series of 2,3-unsaturated glycosides were obtained from 3,4,6-tri-O-acetyl-d -glucal or 3, 4,4-di-O -acetyl -l -rhamnal under mild reaction conditions in good yield and high anomeric selectivity.
Abstract: By using Sm(OTf)3 as the catalyst, synthesis of 2,3-unsaturated-glycosides has been performed. A series of 2,3-unsaturated glycosides were obtained from 3,4,6-tri-O-acetyl– d -glucal or 3,4-di-O-acetyl- l -rhamnal under mild reaction conditions in good yield and high anomeric selectivity. It was found that under certain conditions, reaction of 3,4-di-O-acetyl- l -rhamnal with thiol leads to temperature-dependent formation of C-1-S and C-3-S product. A temperature-dependent profile of the yield of these two products is given.