- Novel Carbocyclization of a D-Glucose-derived Alkene
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Cyclopentadiene reacts with a D-glucose-derived hex-3-enose derivative to give norbornene derivatives attached at the 2,3-position of a 1,6-anhydrohexose skeleton; although the bicyclic enone isolevoglucosenone is a plausible intermediate in this reaction, the products actually appear to arise through initial cycloaddition to a rearranged acyclic sugar derivative with subsequent generation of the anhydro ring.
- Horton, Derek,Roski, James P.
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- Synthesis of novel N-carbohydrate-derived heterocyclic compounds by nucleophilic substitution reaction of carbohydrate imidazole-1-sulfonates
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The nucleophilic substitution reaction of carbohydrate imidazole-1- sulfonates with pyrrole and other nitrogen heterocyclic compounds is reported for the first time. Several novel N-carbohydrate-derived heterocyclic compounds have been prepared by this displacement reaction. The desired carbon-nitrogen bond formation proceeds under mild conditions to generate the coupling products in good yields with readily available and inexpensive reagents. This method is particularly suitable for carbohydrate imidazole-1-sulfonates of primary alcohols. Supplemental materials are available for this article. Go to the publisher's online edition of Journal of Carbohydrate Chemistry to view the free supplemental file. Taylor & Francis Group, LLC.
- Huo, Shiyong,Li, Yueqing,Liang, Chaoyan,Liu, Jihong,Zhao, Weijie
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- A Mechanistic Study of the Photoreactions of Deoxy Iodo Sugars
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Quantum yields of 0.31, 3.7, and 1.1 have been determined for the photochemical disappearance in heptane of 6-deoxy-6-iodo-1,2:3,4-di-O-isopropylidene-α-D-galactopyranose (1), 3-deoxy-3-iodo-1,2:5,6-di-O-isopropylidene-α-D-allofuranose (2), and 3-deoxy-3-iodo-1,2:3,4-di-O-isopropylidene-α-D-glucofuranose (3), respectively.The major reaction for compounds 2 and 3 is epimerization at C-3, a reaction not observable for compound 1.Photochemical epimerization takes place in at least two ways.First, carbon-iodine bond homolysis followed by recombination of the radicalsproduced either regenerates the starting iodide or gives its C-3 epimer.Second, a chain reaction takes place in which the propagation step involves transfer of an iodine atom from the deoxy iodo sugar (2 or 3) to the carbon radical produced by carbon-iodine bond homolysis.In the presence of oxygen a new set of photoproducts is formed.These include enol esters, alcohols, and carbonyl compounds.
- Roth, Richard C.,Binkley, Roger W.
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- Cross dehydrogenative coupling of sugar enol ethers with terminal alkenes in the synthesis of pseudo-disaccharides, chiral oxadecalins and a conjugated triene
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An efficient strategy for the synthesis of C-2 and C-3 branched sugar dienes via cross dehydrogenative coupling of sugar enol ethers with terminal alkenes was developed. Both pyran and furan based enol ethers coupled smoothly with electron rich as well as deficient alkene sources yielding sugar dienes with complete E-stereoselectivity. This coupling reaction was applied successfully for the synthesis of orthogonally protected pseudo-C-saccharides as an alternative to olefin metathesis. Substrate scope was further enhanced by reacting exoglycals with methyl acrylate to generate C-5 branched sugars with moderate diastereoselectivity. These diene subunits were reacted with maleic anhydride under [4 + 2] cycloaddition conditions to generate highly functionalised chiral oxadecalin cores. Finally, utilizing this C-C bond formation, a sugar based conjugated triene was synthesized in excellent yield and selectivity.
- Hussain, Nazar,Babu Tatina, Madhu,Mukherjee, Debaraj
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- Formal synthesis of fostriecin by a carbohydrate-based approach
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The formal synthesis of fostriecin starting from d-glucose, involves chelation-controlled addition, Wittig rearrangement, ring closing metathesis and iodomethylenation, as described.
- Yadav,Prathap,Tadi, Bulli Padmaja
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- Cycloaddition of cyclopentadiene to 3-deoxy-1,2:5,6-di-O-isopropylidene-α-D-erythro-hex-3-enofuranose. Synthesis and representative chemistry of 1,6-anhydro-2,3-dideoxy-β-D-glycero-hex-2-enopyran-4-ulose ("isolevoglucosenone")
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Treatment of D-glucose-derived alkene 4 with cyclopentadiene in the presence of a Lewis acid results in the formation of cycloaddition products 8-11. Evidence is presented to show that these 1,6-anhydro sugar-cyclopentadiene adducts do not arise from rearrangement of 4 to isolevoglucosenone (5) followed by cycloaddition but are the result of Lewis acid-catalyzed rearrangement of alkene 4 to acyclic dienophile 12 followed by addition of cyclopentadiene. Major cycloadduct 8 has been utilized as a source of the enantiomerically pure carbocycles 14-25 by manipulation of the alkene and ketone functions and cleavage of the 1,6-anhydro bridge. In the absence of diene, alkene 4 undergoes rearrangement to enone 5 in 32% yield. Reaction of 5 with several dienes results only in the formation of "bottom-face" adducts 10, 11, 28, and 29, and conjugate addition of either HN3 or Me3COOH is found to be completely stereoselective to afford 30 and 31, respectively. Subsequent manipulation of azide 30 leads to precursors of several naturally occurring 2-amino-2,3-dideoxy sugars.
- Horton, Derek,Roski, James P.,Norris, Peter
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- Studies on the Total Synthesis of Antibiotic Macrolactin S: A Conventional Approach for the Synthesis of the C1-C9 and C10-C24 Fragments
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The C1-C9 and C10-C24 segments of the 24-membered polyene macrolide macrolactin S were synthesized by routes involving an epoxide-ring-opening reaction, an Ohira-Bestmann alkyne formation, a chelation-controlled nucleophilic addition reaction, and a Still
- Sayini, Ramakrishna,Srihari, Pabbaraja
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p. 663 - 675
(2017/11/27)
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- C-3 epimers of sugar amino acids as foldameric building blocks: improved synthesis, useful derivatives, coupling strategies
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To obtain key sugar derivatives for making homooligomeric foldamers or α/β-chimera peptides, economic and multigram scale synthetic methods were to be developed. Though described in the literature, the cost-effective making of both 3-amino-3-deoxy-ribofuranuronic acid (H–tX–OH) and its C-3 epimeric stereoisomer, the 3-amino-3-deoxy-xylofuranuronic acid (H–cX–OH) from d-glucose is described here. The present synthetic route elaborated is (1) appropriate for large-scale synthesis; (2) reagent costs reduced (e.g. by a factor of 400); (3) yields optimized are ~80% or higher for all six consecutive steps concluding –tX– or –cX– and (4) reaction times shortened. Thus, a new synthetic route step-by-step optimized for yield, cost, time and purification is given both for d-xylo and d-ribo-amino-furanuronic acids using sustainable chemistry (e.g. less chromatography with organic solvents; using continuous-flow reactor). Our study encompasses necessary building blocks (e.g. –X–OMe, –X–OiPr, –X–NHMe, Fmoc–X–OH) and key coupling reactions making –Aaa–tX–Aaa– or –Aaa–tX–tX–Aaa– type “inserts”. Completed for both stereoisomers of X, including the newly synthesized Fmoc–cX–OH, producing longer oligomers for drug design and discovery is more of a reality than a wish.
- Nagy, Adrienn,Csordás, Barbara,Zsoldos-Mády, Virág,Pintér, István,Farkas, Viktor,Perczel, András
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p. 223 - 240
(2017/02/05)
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- One-pot stereoselective double intramolecular oxymercuration: Synthesis of four isomers of an unsymmetrical bis-tetrahydrofuran ring system
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Stereoselective one-pot double intramolecular oxymercuration has been demonstrated to be the key reaction in the efficient preparation of the mono-hydroxylated bis-tetrahydrofuran ring system present in asimitrin and salzmanolin, two naturally occurring b
- Mohapatra, Debendra K.,Naidu, P. Ramesh,Reddy, D. Srinivas,Nayak, Sabita,Mohapatra, Seetaram
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body text
p. 6263 - 6268
(2010/12/25)
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- Synthesis of oligosaccharide mimetics with glycoaminoxy acids
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From readily available di-O-isopropylidene-D-glucose, a Dribofuranoid glycoaminoxy acid and its τBu ester have been efficiently prepared as a new family of sugar building blocks by introducing the phthallmido aminoxy group by a Mitsunobu reaction. We found that the τBu ester can be selectively deprotected with 13.7% TFA in CH2Cl2 at 0°C in the pres-ence of the 1,2-O-isopropylldene acetal. This selective deprotection has made possible the synthesis of homo-oligomers of glycoaminoxy acids (up to six sugar units) as a novel type of oligosaccharide mimetics,
- Gong, Yanchun,Sun, Hongbin,Xie, Juan
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scheme or table
p. 6027 - 6033
(2010/03/25)
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- Preparation of oseltamivir phosphate (Tamiflu) and intermediates starting from D-glucose or D-xylose
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Novel processes for the preparation of the anti-viral agent, Oseltamivir Phosphate and novel intermediates prepared in such processes. The novel processes use as starting materials D-glucose or D-xylose in the preparation of Oseltamivir Phosphate.
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Page/Page column 8
(2010/11/29)
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- Biologically potent L-hexoses and 6-deoxy-L-hexoses: Their syntheses and applications
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This account describes our recent work in the development of new methodologies to prepare rare and biologically potent L-hexoses and 6-deoxy-L-hexoses, from cheapest D-glucose, via L-hexofuranoses and 1,6-anhydro-β-L-hexopyranoses as key building blocks. Their applications in the syntheses of heparin oligosaccharides, the carbohydrate moiety of bleomycin A2, and L-acovenose are also summarized here.
- Kulkarni, Suvarn S.,Chi, Fa-Chen,Hung, Shang-Cheng
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p. 1193 - 1200
(2007/10/03)
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- Nucleophilic displacement reactions in ionic liquids: Substrate and solvent effect in the reaction of NaN3 and KCN with alkyl halides and tosylates
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Room-temperature ionic liquids have been used as environmentally benign solvents for the preparation of primary and secondary alkyl azides and nitriles under solid-RTIL phase-transfer conditions. The reaction of primary, secondary, and tertiary halides or tosylates with KCN and NaN3 has been investigated in three ionic liquids ([bmim][PF6], [bmim][N(Tf) 2], and [hpyr] [N(Tf)2]). The observed nucleofugacity scales for the reaction of NaN3 are similar to those reported for the same process in cyclohexane, indicating that in these solvents it is possible to evidence the intrinsic ability to depart of leaving groups. Changes in the nature of the IL cation or anion determine significant modifications in reactivity of the investigated substrates. Reactivity has been interpreted considering a gradual shift of the mechanism from concerted SN2 (primary substrates) to stepwise SN1 (tertiary substrate, 3), through the nucleophilically assisted formation of an ion pair intermediate, in the case of 2d.
- Chiappe, Cinzia,Pieraccini, Daniela,Saullo, Paola
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p. 6710 - 6715
(2007/10/03)
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- Practical synthesis of [1-13C]- and [6-13C]-D-galactose
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The chemical synthesis of 13C-labeled D-galactose as useful molecular probes for studying the conformation of oligosaccharides attached to proteins was performed. The method for synthesizing the title labeled compounds was newly developed via t
- Sato, Ken-Ichi,Akai, Shoji,Sakuma, Mayumi,Kojima, Masaru,Suzuki, Ken-Ju
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p. 4903 - 4907
(2007/10/03)
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- Synthesis of 2-(3′-Azido- and 3′-Amino-3′-deoxy-β -D-ribofuranosyl)thiazole-4-carboxamide
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In view of biological activities of tiazofurin and azido or aminosugar nucleosides, novel azido- and amino -substituted tiazofurin derivatives (1 and 2) were efficiently synthesized starting from 1,2; 5,6-di-O-isopropylidene-D-glucose.
- Liang, Cheng Wu,Kim, Myong Jung,Jeong, Lak Shin,Chun, Moon Woo
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p. 2039 - 2048
(2007/10/03)
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- Efficient synthesis of L-altrose and L-mannose
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Two convenient routes for the synthesis of L-altrose and L-mannose from 1,2:3,5-di-O-isopropylidene-β-L-idofuranose in four and six steps via the stereoselective hydroboration and hydrogenation of olefins as key steps are described here, respectively. (C) 2000 Elsevier Science Ltd.
- Hung, Shang-Cheng,Wang, Cheng-Chung,Thopate, Shankar R.
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p. 3119 - 3122
(2007/10/03)
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- 3-Azidotetrahydrofuran-2-carboxylates: Monomers for five-ring templated β-amino acid foldamers?
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Four diastereomeric methyl 3-azidotetrahydrofuran-2-carboxylates were prepared from diacetone glucose as precursors for the synthesis of β-amino acid oligomers with secondary structure.
- Watterson, Mark P.,Pickering, Lea,Smith, Martin D.,Hudson, Sarah J.,Marsh, Paul R.,Mordaunt, Jacqueline E.,Watkin, David J.,Newman, Christopher J.,Fleet, George W. J.
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p. 1855 - 1859
(2007/10/03)
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- Synthesis of 6-hydroxy-L-daunosamine and L-daunosamine derivatives
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Methyl 3-trifluoroacetamido-2,3-dideoxy-α-L-lyxo-hexopyranoside (19) has been synthesized from D-glucose derivatives following two pathways. The first one involving 1,2:5,6-di-O-isopropylidene-α-D-glucopyranose as starting material is mainly based upon az
- Daley, Laurent,Roger, Pierre,Monneret, Claude
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- α- And β-hydrogen eliminations in the reactions of some 3-O-triflylglycosides with (t)BuOK and pyridine
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Previous papers [10-12] reported new reactions that occur when some carbohydrate triflates are treated with MeLi (or BuLi) in Et2O to give the C-methyl(butyl) or unsaturated compounds through elimination of the CH-hydrogen bearing a CF3SO3 group ( α-elimination) as a proton. This paper extends the previous work and describes the reactions for some 3-O-triflyl-D-gluco- and -allo-furanosides and -pyranosides with (t)BuOK and pyridine [instead of Me(Bu)Li], utilizing the corresponding 2- and 3-deuterated analogs. It was found that, when (t)BuOK was used, the 3-O-triflyl-D-glucopyranosides gave 2,3- and 3,4-unsaturated compounds through a-hydrogen elimination (a-elimination) followed by (possibly) C-3 carbene formation, while the 3-O-triflyl-D-allopyranosides gave mainly 2,3-unsaturated compounds through p-elimination. When pyridine was used, most of the compounds gave the corresponding 3-pyridinium derivatives through an SN2 process.
- El Nemr, Ahmed,Tsuchiya, Tsutomu
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p. 267 - 281
(2007/10/03)
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- Design and reactivity of organic functional groups - Preparation and nucleophilic displacement reactions of imidazole-1-sulfonates (imidazylates)
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Imidazole-1-sulfonate, a new type of leaving group by remote activation, allows facile S(N)2 substitution reactions at sterically crowded centers with various nucleophiles under mild conditions. It could be easily prepared from alcohols with cheap reagent
- Vatele, Jean-Michel,Hanessian, Stephen
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p. 10557 - 10568
(2007/10/03)
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- α-Hydrogen Elimination in Some Carbohydrate Triflates
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In some carbohydrate triflates, treatment with MeLi (or BuLi) in ether caused α-hydrogen elimination initially, then the resulting carbanion is stabilized to give either C-methyl(or butyl)-hydroxy derivatives or unsaturated products.
- Nemr, Ahmed El,Tsuchiya, Tsutomu
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p. 7665 - 7668
(2007/10/02)
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- Aureolic acid antibiotics: Synthesis of the cyclohexenone segment from D-glucose
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The cyclohexenone segment which is common to all the aureolic acid group of antibiotics has been synthesised from D-glucose.Two routes have been designed to obtain methyl 3-O-benzyl-6-deoxy-2-O-methyl-D-galactopyranoside.Route-A involves the introduction
- Gurjar, M.K.,Devi, T. Rama,Reddy, K.L.N.,Sharma, P.A.,Dhar, T.G. Murali
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p. 995 - 1003
(2007/10/02)
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- AN IMPROVED SYNTHESIS OF METHYL N-TRIFLUOROACETYL-6-HYDROXY-α-L-DAUNOSAMINIDE
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2,3-Dideoxy-3-trifluoroacetamido-L-lyxo-hexose (or N-trifluoroacetyl-6-hydroxy-L-daunosamine) 13 has been synthesized from diacetone-D-glucose 1 in 13 steps and approximately 10percent overall yield. Key words: aminodeoxysugars, triflate derivatives, azid
- Daley, Laurent,Monneret, Claude,Gautier, Claudie,Roger, Pierre
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p. 3749 - 3752
(2007/10/02)
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- The mechanism of the hydroxyl → halogen exchange reaction in the presence of triphenylphosphine, N-bromosuccinimide, and N,N-dimethylformamide: Application of a new Vilsmeier-type reagent in carbohydrate chemistry
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Triphenylphosphine reacts with N-bromosuccinimide to give a phosphonium salt (13), which reacts with N,N-dimethylformamide to afford N,N-dimethylsuccinimidomethaniminium bromide (16). The latter product reacts with an alcohol to give an O-formiminium compound 17, and, in the presence of an alcohol, 13 is transformed into an alkoxyphosphonium intermediate (14). Both 4 and 17 can be converted by heating into an alkyl bromide. Hydrolysis of 17 gives the corresponding O-formyl derivative. Reaction of 1.2:5.6-di-O-isopropylidene-α-D-glucofuranose with 13 or 16 gave 6-bromo-6-deoxy-1,2:3,5-di-O-isopropylidene-α-D-glucofuranose and a possible mechanism for these reactions is suggested. An efficient method for the preparation of 3-deoxy-3-halogeno-1,2:5,6-di-O-isopropylidene-α-D-allofuranose derivatives and a new procedure for selective O-formylation are described.
- Hodosi,Podanyi,Kuszmann
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p. 327 - 342
(2007/10/02)
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- Synthesis of the methyl 3-amino-3-deoxy-α- and β-D-allopyranosides and -allofuranosides
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Methyl 3-amino-3-deoxy-α-D-allopyranoside was synthesized from methyl 2-O-benzoyl-4,6-O-benzylidene-α-D-glucopyranoside in a 5-step sequence involving trifluoromethylsulfonylation, azide displacement, deprotection, and catalytic hydrogenation.On displacem
- Baer, Hans H.,Gan, Yuchen
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p. 233 - 245
(2007/10/02)
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- Synthesis of optically active O-protected (S)- and (R)-3-hydroxyaldehydes
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(S)-3-Formyloxyaldehydes, chiral synthons for natural product synthesis were synthesized via highly stereoselective hydrogenation of the unsaturated furanose ring system derived from D-glucose or D-xylose. Alternatively, (R)-3-formyloxyaldehydes were prepared via deoxygenation of 3-hydroxyfuranoses derived from D-glucose or D-xylose.
- Kang, Suk-Ku,Cho, Hyun-Sung
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p. 367 - 370
(2007/10/02)
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- Highly Selective Metal-Graphite-Induced Reductions of Deoxy Halo Sugars
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To explore the applicability of highly active metal-graphite reducing agents to polyfunctional compounds a variety of suitably protected chloro-, bromodeoxy-, and deoxyiodohexopyranosides and hexofuranoses were each treated with potassium-graphite laminat
- Fuerstner, Alois,Weidmann, Hans
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p. 2307 - 2311
(2007/10/02)
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- APPLICATION OF STERICALLY CROWDED ALKYL SULFONATES : SN2-SUBSTITUTION IN THE DIACETONE GLUCOSE SYSTEM
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The hitherto unaccessible C-substitution by O-nucleophiles in glucose sulfonates 4 was achieved by high nucleofugality of the leaving group and steric hindrance within the ester part of 4b.
- Netscher, Thomas
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p. 455 - 458
(2007/10/02)
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- Utility of Tris(dimethylamino)sulphonium Difluorotrimethylsilicate (TASF) for the Rapid Synthesis of Deoxyfluoro Sugars
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The fluoride ion displacement of carbohydrate trifluoromethanesulphonates using tris(dimethylamino)sulphonium difluorotrimethylsilicate (TASF) provides a convenient route to deoxyfluoro sugars; the rapidity of the reaction makes it of interest for the pot
- Szarek, Walter A.,Hay, George W.,Doboszewski, Bogdan
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p. 663 - 664
(2007/10/02)
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- Synthesis and Reactions of 3-O-Phosphoniogluco- and Allofuranoses
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Starting from the bicyclic gluco- (3,5,7, and 9) and allofuranoses 11 the isolable 3-O-phosphoniocarbohydrates (4,6,8,10, and 12) were synthesized by reaction with triphenylphosphane (1), diethyl azodicarboxylate (2), and alkylating or acylating agents.On heating, the various allo configurated salts 12 are converted into the corresponding at C-3 epimeric gluco configurated substitution products offering a wide range of flexibility.The reactions of the gluco configurated salts depend strongly on the type of nucleophile to be introduced and from neighboring groups in t he carbohydrate skeleton.The iodide 4a and the azide 4g react by substitution forming the allo derivatives 15.In contrast, bromide, chloride, and sulfonate as gegen-ions mainly cause rearrangement of the 5,6-isopropylidene bridge or opening of the 5,6-anhydro structure.
- Kunz, Horst,Schmidt, Peter
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p. 1245 - 1260
(2007/10/02)
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- The Reaction of N-Dichloromethylene-N,N-dimethylammonium chloride (Viehe's Salt) with 1,2:5,6-Di-O-isopropylidene-α-D-glucose
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The treatment of 1,2:5,6-di-O-isopropylidene-α-D-glucose with N-dichloromethylene-N,N-dimethylammonium chloride (Viehe's salt) (2:1 or 1:1) gives two iminium salts.These are readily hydrolysed to a carbonate and a carbamate.Treatment with sodium hydrogen
- Copeland, Christopher,Stick, Robert V.
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p. 2269 - 2275
(2007/10/02)
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