- Cesium carbonate-promoted Michael-type addition of thiols to hex-1-en-3-ulose: A practical synthesis of 2-deoxy-1-thio-α-hexopyranosid- 3-ulose template
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The template 2-deoxy-1-thio-α-hexopyranosid-3-ulose was synthesized in quantitative yield and high diastereoselectivity by 1,4-addition of aryl and alkyl thiols to hex-1-en-3-ulose promoted by cesium carbonate in THF. Copyright Taylor & Francis Group, LLC
- Ganguly, Debashis,Tang, Haiqun,Rodriguez, Michael J.
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- Studies directed toward the total synthesis of Scytophycin C: Synthesis of the C(1)-C(18) fragment of Scytophycin C
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The synthesis of the C(1) to C(18) fragment of Scytophycin C is described which features a highly stereoselective carbon Ferrier-type reaction in 3.0 M lithium perchlorate/ethyl acetate.
- Grieco, Paul A.,Speake, Jason D.
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- C-glycosides and C-disaccharide precursors through carbonylative stille coupling reactions
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Under CO atmosphere and in the presence of Pd2(dba)3 and Ph3As a suitably protected 1-stannylglucal derivative could be carbonylated and coupled to 5-bromo-7-oxabidyclo[2.2.1]hept-5-en-2-yl derivatives. The carbonylative Stille coupling was also successful between 1-iodoglucals and tributyl(vinyl)stannane or tributyl(fur-2-yl)stannane. A cross-conjugated dienone was also obtained through coupling of a 1-stannylglucal with a 1-iodoglucal derivative.
- Jeanneret, Vincent,Meerpoel, Lieven,Vogel, Pierre
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- Syntheses of new bidentate thioethylphosphine ligands and their rhodium (I) complexes with carbohydrates as chiral groups
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Substitution-, addition-and rearrangement reactions on easily available derivatives of carbohydrates (1, 2 and 4) with diphenylvinylphosphine or 2-mercaptoethyldiphenylphosphine gave chiral bidentate β-thioethylphosphine ligands (5-9). These compounds for
- Borwitzky, Angela,Schareina, Thomas,Paetzold, Eckhard,Oehme, Guenther
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- A concise, enantioselective synthesis of (+)-decarestrictine L from Tri-O-acetyl-D-glucal
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We describe a new and efficient approach to the enantioselective synthesis of (+)-(2R,3S,6R)-decarestrictine L from commercially available tri-O-acetyl-D-glucal, based on a stereoselective Michael addition. Georg Thieme Verlag Stuttgart · New York.
- Zuniga, Andrea,Perez, Manuel,Pazos, Gonzalo,Gomez, Generosa,Fall, Yagamare
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- Enantioselective Synthesis of a Cyclopropane Derivative of Spliceostatin A and Evaluation of Bioactivity
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Spliceostatin A is a potent inhibitor of spliceosomes and exhibits excellent anticancer activity against multiple human cancer cell lines. We describe here the design and synthesis of a stable cyclopropane derivative of spliceostatin A. The synthesis invo
- Ghosh, Arun K.,Reddy, Guddeti Chandrashekar,Kovela, Satish,Relitti, Nicola,Urabe, Veronica K.,Prichard, Beth E.,Jurica, Melissa S.
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- Enantioselective Synthesis of Spliceostatin G and Evaluation of Bioactivity of Spliceostatin G and Its Methyl Ester
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An enantioselective total synthesis of spliceostatin G has been accomplished. The synthesis involved a Suzuki cross-coupling reaction as a key step. The functionalized tetrahydropyran ring was constructed from commercially available optically active tri-O-acetyl-d-glucal. Other key reactions include a highly stereoselective Claisen rearrangement, a Cu(I)-mediated 1,4 addition of MeLi to install the C8 methyl group, and a reductive amination to incorporate the C10 amine functionality of spliceostatin G. Biological evaluation of synthetic spliceostatin G and its methyl ester revealed that it does not inhibit splicing in vitro.
- Ghosh, Arun K.,Reddy, Guddeti Chandrashekar,MacRae, Andrew J.,Jurica, Melissa S.
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- Enantioselective Synthesis of Thailanstatin A Methyl Ester and Evaluation of in Vitro Splicing Inhibition
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Thailanstatin A has been isolated recently from the fermentation broth of B. thailandensis MSMB43. We describe here an enantioselective convergent synthesis of thailanstatin A methyl ester and evaluation of its splicing activity. Synthesis of both highly functionalized tetrahydropyran rings were carried out from commercially available tri-O-acetyl-d-glucal as the key starting material. Our convergent synthesis involved the synthesis of both tetrahydropyran fragments in a highly stereoselective manner. The fragments were then coupled using cross-metathesis as the key step. The synthesis of the diene subunit included a highly stereoselective Claisen rearrangement, a Cu(I)-mediated conjugate addition of MeLi to set the C-14 methyl stereochemistry, a reductive amination reaction to install the C16-amine functionality, and a Wittig olefination reaction to incorporate the diene unit. The epoxy alcohol subunit was synthesized by a highly selective anomeric allylation, a Peterson olefination, and a vanadium catalyzed epoxidation that installed the epoxide stereoselectively. Cross-metathesis of the olefins provided the methyl ester derivative of thailanstatin A. We have carried out in vitro splicing studies of the methyl ester derivative, which proved to be a potent inhibitor of the spliceosome.
- Ghosh, Arun K.,Veitschegger, Anne M.,Nie, Shenyou,Relitti, Nicola,Macrae, Andrew J.,Jurica, Melissa S.
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- AN APPROACH TO THE SYNTHESIS OF OPTICALLY ACTIVE TRICHOTHECENES FROM TRI-O-ACETYL-D-GLUCAL
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A chiral synthesis of the B-C ring system of trichothecenes from tri-O-acetyl-D-glucal by using a photochemical cycloaddition of acetylene to the unsaturated ketone 7, followed by acid-catalyzed rearrangement, is described.
- Fetizon, M.,Khac, Duc Do,Tho, Nguyen Dinh
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- Some derivatives of 3-deoxy-D-glycero-D-galacto-non-2-ulosonic acid (KDN)
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Treatment of a solution of 3-deoxy-D-glycero-D-galacto-non-2-ulosonic (KDN) in 11 N aqueous hydrochloric acid with an excess of ethanethiol gave in 52% yield the diethyl dithioacetal of the corresponding 1,4-lactone, which was further characterized as its peracetate. With 1,3-propanedithiol, only one thiol function reacted and the product, isolated in 18% yield as its peracetate, was a vinyl thioether of the α,β-unsaturated 1,4-lactone. The methyl ester methyl β-glycopyranoside derivative of KDN could be converted to the 8,9-isopropylidene ketal 7 (69%). Conditions were found which allow selective silylation at C-4 with tert-butylchlorodimethylsilane, giving the 4-O-tert-butylsilyl derivative in 91% yield. Heating it with bis(tributyltin) oxide afforded the 1,7-lactone with inversion of the ring conformation. Lithium aluminium hydride reduction of 7 afforded the corresponding methyl non-2-ulopyranoside, which was converted to the 1,4-bis(silyl) ether. Bromination of 1,5-anhydro-2-deoxy-D-arabino-hex-1-enitol in aqueous solution at 0°C with N-bromophthalimide gave a mixture of bromodeoxy hexoses from which 2-bromo-2-deoxy-D-mannose was isolated in 60% yield by crystallization. Its incubation with pyruvate in the presence of sialyl aldolase gave 5- bromo-3,5-dideoxy-D-glycero-D-galacto-non-2-ulosonic acid 16 in 70% yield. Treatment of a solution of 3-deoxy-D-glycero-D-galacto-non-2-ulosonic (KDN) in 11 N aqueous hydrochloric acid with an excess of ethanethiol gave in 52% yield the diethyl dithioacetal of the corresponding 1,4-lactone, which was further characterized as its peracetate. With 1,3-propanedithiol, only one thiol function reacted and the product, isolated in 18% yield as its peracetate, was a vinyl thioether of the α,β-unsaturated 1,4-lactone. The methyl ester methyl β-glycopyranoside derivative of KDN could be converted to the 8,9-isopropylidene ketal 7 (69%). Conditions were found which allow selective silylation at C-4 with tert-butylchlorodimethylsilane, giving the 4-O-tert-butylsilyl derivative in 91% yield. Heating it with bis(tributyltin) oxide afforded the 1,7-lactone with inversion of the ring conformation. Lithium aluminium hydride reduction of 7 afforded the corresponding methyl non-2-ulopyranoside, which was converted to the 1,4-bis(silyl) ether. Bromination of 1,5-anhydro-2-deoxy-D-arabino-hex-1-enitol in aqueous solution at 0°C with N-bromophthalimide gave a mixture of bromodeoxy hexoses from which 2-bromo-2-deoxy-D-mannose was isolated in 60% yield by crystallization. Its incubation with pyruvate in the presence of sialyl aldolase gave 5-bromo-3,5-dideoxy-D-glycero-D-galacto-non-2-ulosonic acid 16 in 70% yield.
- David,Malleron,Cavaye
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- ADDITION OF HALOGENOAZIDES TO GLYCALS
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Addition of chloroazide to 3,4,6-tri-O-acetyl-1,5-anhydro-2-deoxy-D-lyxo- (1) and -D-arabino-hex-1-enitol (2) under u.v. irradiation proceeds regio- and stereo-selectively yielding mainly O-acetyl derivatives of 2-azido-2-deoxy-D-galactopyranose and -D-glucopyranose, respectively. 3,4,6-Tri-O-acetyl-2-azido-2-deoxy-α-D-galactopyranosyl azide and 3,4,6-tri-O-acetyl-2-azido-2-deoxy-α-D-talopyranose (from 1), and 1,3,4,6-tetra-O-acetyl-2-chloro-2-deoxy-α-D-glucopyranosyl azide and 1,3,4,6-tetra-O-acetyl-2-azido-2-deoxy-α-D-mannopyranose (from 2) are byproducts. 1,5-Anhydro-3,4,6-tri-O-benzyl-2-deoxy-D-lyxo- and -D-arabino-hex-1-enitol reacted more rapidly with chloroazide, to give, under irradiation, derivatives of 2-azido-2-deoxy-D-galactose and -D-glucose, respectively.However, reaction in the dark gave mainly O-benzyl derivatives of 2-chloro-2-deoxy-α-D-galacto- and -α-D-glucopyranosyl azide.The difference between the products obtained may depend on the existence of two parallel processes, one radical (under irradiation), and the other ionic (reaction in the dark).
- Bovin, Nicolai V.,Zurabyan, Sergei E.,Khorlin, Anatoly Y.
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- Synthesis of 2′-paclitaxel 2-deoxy-2-fluoro-glucopyranosyl carbonate for specific targeted delivery to cancer cells
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A novel 2-fluorodeoxyglucose conjugated derivative of paclitaxel was efficiently synthesized using a linker between 2′-OH of paclitaxel and C1-hydroxyl group of 2-fluorodeoxyglucose. In preparation of the prodrug, allyl carbonates were selected as the protective group and the efficient one-step removal of allyloxycarbonyl groups at the end of the synthesis using palladium chemistry gave the target molecule in good yield. The prodrug not only improved the pharmaceutical properties of paclitaxel, such as solubility and stability, but also demonstrated enhanced cytotoxicity and selectivity for cancer cells and less toxicity toward normal HUVEC cells.
- Li, Tingshen,Li, Xiao,Lian, Xujing,Meng, Xin,Ya, Qiang,Yang, Yang,Zhang, Yan,Zhang, Yongmin
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- Facile Approaches to 2-Deoxy- d -glucose and 2-Deoxy-α- d -glucopyranonucleosides from d -Glucal
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Convenient and stereoselective methods for the preparation of 2-deoxy- d -glucose and purine 2-deoxy-α- d -glucopyranonucleosides were developed. Halogen-mediated O-glycosidation of d -glucal by bromine in MeOH followed by reductive removal of the halo group and hydrolysis of methoxy group by zinc in saturated aqueous sodium dihydrogen phosphate gave 2-deoxy- d -glucose. Treatment of 3,4,6-tri- O -acetyl- d -glucal with IBr and 2,6-dichloropurine based on haloetherification and subsequent reductive removal of iodine and deprotection allowed the isolation of purin-9-yl 2-deoxy-α- d -glucopyranonucleoside. Preparation of several purin-9-yl 2-deoxy-α- d -glucopyranoside derivatives is also reported. Their configuration was confirmed by single crystal X-ray analysis of the key intermediate 2,6-dichloro-9-(2-iodo-2-deoxy-α- d -glucopyranosyl)purine.
- Xu, Wenke,Yang, Hui,Liu, Yingju,Hua, Yingchun,He, Bin,Ning, Xin,Qin, Zhiyan,Liu, Hong-Min,Liu, Feng-Wu
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- 1-[2-(Trimethylsilyl)ethoxy]ethyl (SEE): A novel hybrid hydroxy-protecting group between 1-(ethoxy)ethyl (EE) and 2-(trimethylsilyl)ethoxymethyl (SEM)
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The highly versatile 1-[(2-trimethylsilyl)ethoxy]ethyl (SEE) group, readily obtainable from an alcohol and 2-(trimethylsilyl)ethyl vinyl ether in the presence of a catalytic amount of PPTS, has been developed for the protection of hydroxyl groups. Its deprotection can be achieved under virtually neutral conditions with the use of a fluoride ion source, thus allowing for effective protection of hydroxyl groups of compounds that contain acid- and/or base-sensitive functional groups.
- Wu, Junjun,Shull, Brian K.,Koreeda, Masato
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- Synthesis of novel migrastatin and dorrigocin A analogues from D-glucal
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The synthesis of a range of analogues of the migrastatin macrolide core has been achieved from tri-O-acetyl-D-glucal in order to facilitate structure-activity studies. Efficient macrolactone formation was achieved in the presence of a reactive olefin, by
- Anquetin, Guillaume,Rawe, Sarah L.,McMahon, Kevin,Murphy, Evelyn P.,Murphy, Paul V.
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- An electrophile-mediated cyclization on the 1,6-anhydro-D-glucopyranose framework
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Iodocyclization of O-tributylstannyl-D-glucal with iodine in acetonitrile gave 1,6-anhydro-2-deoxy-2-iodo-β-D-glucopyranose (1) in high yield.The 3,4-di-O-acetyl derivative of 1 could be converted into the corresponding 2-deoxy compound and into the 2-C-allyl-2-deoxy branched sugar (5) by treatment with tributylstannane and allyltributylstannane, respectively.Controlled alkaline hydrolysis of 5 gave the 4-monoacetyl derivative.Complete hydrolysis of 5 gave the 3,4-diol, which underwent a 5-exo cyclization by treatment with N-bromosuccinimide. 1H NMR spectroscopy and X-ray analysis showed that the cyclized product has the B3,0 conformation in its pyranose ring, which is trans-fused to the newly formed tetrahydrofuran ring.
- Leteux, Christine,Veyrieres, Alain,Robert, Francis
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- Synthesis and end group structure of 2-deoxydextrans prepared via the cationic ring-opening polymerization of an anhydro sugar
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1,6-Anhydro-3,4-di-O-benzyl-2-deoxy-β-D-glucose was polymerized using 1-chloroethyl isobutyl ether or cumyl chloride as initiator and ZnI2 as activator. The resulting polymer contained predominantly α-(1,6) linkages, and the molecular weight distributions were narrow (≤ 1.25). The kinetics of polymerization was first-order with respect to monomer concentration. There was evidence of slow chain transfer at these polymerization temperatures, although the majority of polymer chains contained the initiator fragment. Mass spectra of the polymer revealed that the initiator fragment at the polymer chain end was an isobutyl group, presumably arising from nucleophilic attack of monomer on the methylene unit of the isobutyl group in the initiating cation with loss of acetaldehyde as opposed to attack at the Sp2-methylene carbon. Cyclic oligomers were present in the polymer sample as well and could have arisen from two processes: HCl initiation or a backbiting reaction.
- Liang, Yu-Zeng,Franz, Andreas H.,Newbury, Chrisana,Lebrilla, Carlito B.,Patten, Timothy E.
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- Aziridine Ring Opening as Regio-and Stereoselective Access to C-Glycosyl-Aminoethyl Sulfide Derivatives
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A short synthetic route to stereoselective access to C-glycosyl-aminoethyl sulfide derivatives has been developed through the reaction of tributhyltin derivatives of glycals with aziridinecarboaldehyde and the regioselective ring opening of a chiral aziridine with thiophenol. The absolute configurations of the resulting diastereoisomers were determined by 1H NMR spectroscopy.
- Le?niak, Stanis?aw,Malinowska, Martyna,Tracz, Aleksandra,Zawisza, Anna
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- Me3SI-promoted chemoselective deacetylation: a general and mild protocol
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A Me3SI-mediated simple and efficient protocol for the chemoselective deprotection of acetyl groups has been developedviaemploying KMnO4as an additive. This chemoselective deacetylation is amenable to a wide range of substrates, tolerating diverse and sensitive functional groups in carbohydrates, amino acids, natural products, heterocycles, and general scaffolds. The protocol is attractive because it uses an environmentally benign reagent system to perform quantitative and clean transformations under ambient conditions.
- Gurawa, Aakanksha,Kashyap, Sudhir,Kumar, Manoj
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p. 19310 - 19315
(2021/06/03)
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- Method for efficiently constructing 1, 2-cis-2-nitro-glucoside and galactoside
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The invention discloses a method for efficiently constructing 1, 2-cis-2-nitro-glucoside and 1, 2-cis-2-nitro-galactoside, and belongs to the technical field of organic synthesis. According to the preparation method, the 1, 2-cis-2-nitro-glucoside and the 1, 2-cis-2-nitro-galactoside can be efficiently prepared through one-step synthesis. According to the present invention, the organic catalysis stereoselective glycosylation method is successfully applied to the sugar chemical total synthesis so that the problem of the construction of the 1, 2-cis-glucosidic bond between the most key sugar units is solved, and the foundation is established for the completion of the subsequent poly O-antigen total synthesis. The work has important reference value for related immunological research and vaccine development in the future.
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Paragraph 0038; 0063; 0064
(2021/08/11)
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- 2-nitroglycal and efficient synthesis method thereof
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The invention discloses an efficient synthesis method of 2-nitroglycal, and belongs to the technical field of synthesis of sugar. The structure of the 2-nitroglycal is shown in the specification. Secondly, the invention also provides a preparation method of the 2-nitro saccharide alkene, and the preparation method provided by the invention can be used for efficiently preparing the 2-nitroglycal through one-step synthesis.
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Paragraph 0056-0058
(2021/08/06)
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- Water Compatible Hypophosphites- d2 Reagents: Deuteration Reaction via Deutero-deiodination in Aqueous Solution
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Contrary to conventional deuteration approaches which typically entail deuterated solvents and/or moisture exclusion, an unprecedented deutero-deiodination reaction attainable in aqueous (H2O) solution is presented herein. By utilizing the stability of inorganic deuterated calcium/sodium hypophosphites against wayward H/D isotopic exchange within pH 2.5-11.7, these shelf-stable, nontoxic, cost-effective, and environmentally benign deuteration reagents mediate deuteration of a broad range alkyl and aryl iodides with ample isotopic incorporation in aqueous (H2O) solution.
- Fang, Jing,Li, Ting,Meng, Lingkui,Song, Zejin,Wan, Qian,Zeng, Jing,Zhao, Xiang
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supporting information
(2020/03/13)
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- Development of Routes for the Stereoselective Preparation of β-Aryl- C-glycosides via C-1 Aryl Enones
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A wide range of enones derived from d-glucal, d-galactal, l-rhamnal, d-rhamnal, and l-arabinal underwent Heck-coupling with various arylboronic acids bearing electron-donating and -withdrawing groups in the presence of palladium acetate and 1,10-phenanthroline. These reactions provided synthetically useful C-1 aryl enones in good yields. Many sensitive functional groups as well as protecting groups present in arylboronic acids and enones, respectively, remained intact under optimized conditions. The stereoselective hydrogenation of C-1 aryl enones with Pd-C/H2 provides the β-isomer of 2-deoxy-aryl-C-glycosides in excellent yield. The C-1 aryl enones were also used as precursors for the synthesis of 2-hydroxy-β-aryl-C-glycosides. Regioselective C-2 halogenations and vinylations of C-1 aryl enones were achieved in excellent yields.
- Kanaujiya, Vimlesh Kumar,Kandasamy, Jeyakumar,Sabiah, Shahulhameed,Singh, Adesh Kumar,Tiwari, Varsha
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supporting information
p. 7650 - 7655
(2020/10/09)
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- Formation of five-membered carbocycles from D-glucose: A Concise Synthesis of 4-Hydroxy-2-(hydroxymethyl)cyclopentenone
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A concise synthesis of 4-hydroxy-2-(hydroxymethyl)cyclo-pentenone (1) has been accomplished from D-glucose by a three-step sequence that features a catalyst-free hydrothermal reaction of D-glucal, which is readily obtained from D-glucose. Optimization of the reaction conditions for synthesizing 1 was performed by changing the temperature and reaction time. The treatment of D-glucal under the optimal conditions, i.e., at 120 °C for 24 h, provided 1 in the highest isolated yield of 61%. 1 would become a versatile intermediate for the synthesis of various fine chemicals having a cyclopentenone structure from cellulosic biomass.
- Koseki, Yoshitaka,Watanabe, Toshihiro,Kamishima, Takaaki,Kwon, Eunsang,Kasai, Hitoshi
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p. 1324 - 1328
(2019/09/18)
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- Reagent Controlled Direct Dehydrative Glycosylation with 2-Deoxy Sugars: Construction of the Saquayamycin Z Pentasaccharide
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The first synthesis of the pentasaccharide fragment of the angucycline antibiotic saquayamycin Z is described. By using our sulfonyl chloride mediated reagent controlled dehydrative glycosylation, we are able to assemble the glycosidic linkages with high
- Mizia, J. Colin,Bennett, Clay S.
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supporting information
p. 5922 - 5927
(2019/08/27)
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- Fluoroglycosyl-modified paclitaxel compound and synthesis method and application thereof
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The invention relates to a fluoroglycosyl-modified paclitaxel compound represented by the following structural general formula described in the invention. The paclitaxel compound can be hydrolyzed slowly to release paclitaxel drugs. In-vitro cytotoxicity experiment studies find out that the paclitaxel compound has the same tumor cell killing effect as that of paclitaxel, can be applied in improvement of the water solubility of the paclitaxel compound, and also can be applied in preparation of drugs for treatment or prevention of malignant tumors.
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Paragraph 0138; 0143; 0144
(2019/07/29)
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- NOVEL ACETATES OF 2-DEOXY MONOSACCHARIDES WITH ANTICANCER ACTIVITY
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Novel compounds and methods of using the same to inhibit glycolysis and treat cancer and other diseases are provided herein.
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Paragraph 0096; 0097
(2017/04/01)
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- Synthesis of Altrose Poly-amido-saccharides with β-N-(1→2)- d -amide Linkages: A Right-Handed Helical Conformation Engineered in at the Monomer Level
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The design and synthesis of amide-linked saccharide oligomers and polymers, which are predisposed to fold into specific ordered secondary structures, is of significant interest. Herein, right-handed helical poly amido-saccharides (PASs) with β-N-(1→2)-d-amide linkages are synthesized by the anionic ring-opening polymerization of an altrose β-lactam monomer (alt-lactam). The right-handed helical conformation is engineered into the polymers by preinstalling the β configuration of the lactam ring in the monomer via the stereospecific [2+2] cycloaddition of trichloroacetyl isocyanate with a d-glycal possessing a 3-benzyloxy group oriented to the α-face of the pyranose. The tert-butylacetyl chloride initiated polymerization of the alt-lactam proceeds smoothly to afford stereoregular polymers with narrow dispersities. Birch reduction of the benzylated polymers gives water-soluble altrose PASs (alt-PASs) in high yields without degradation of the polymer backbone. Circular dichroism analysis shows the alt-PASs adopt a right-handed helical conformation in aqueous solutions. This secondary conformation is stable over a wide range of different conditions, such as pH (2.0 to 12.0), temperature (5 to 75 °C), ionic salts (2.0 M LiCl, NaCl, and KCl), as well as in the presence of protein denaturants (4.0 M urea and guanidinium chloride). Cytotoxicity studies reveal that the alt-PASs are nontoxic to HEK, HeLa, and NIH3T3 cells. The results showcase the ability to direct solution conformation of polymers through monomer design. This approach is especially well-suited and straightforward for PASs as the helical conformations formed result from constraints imposed by the relatively rigid and sterically bulky repeating units.
- Xiao, Ruiqing,Dane, Eric L.,Zeng, Jialiu,McKnight, Christopher J.,Grinstaff, Mark W.
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p. 14217 - 14223
(2017/10/17)
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- Efficient and green approach for the complete deprotection of O-acetylated biomolecules
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A simple, efficient and mild strategy for the complete O-deacetylation of different per-acetylated biomolecules in aqueous media has been described. Different lipases were tested but only the commercial Amano lipase A from Aspergillus Niger catalyzed the complete deprotection of peracetylated α-glucose to glucose in excellent yield. The experimental conditions were tested, in particular the pH effect. The reaction was performed at different pHs considering the only enzymatic process was evaluated at pH 5 and the combination of enzymatic and chemical migration process was evaluated at higher pHs. Finally pH 7 and 25 °C were selected as best conditions. Thus this lipase fully hydrolyzed different peracetylated α-glycopyranosides (glucose, mannose, glucal, galactal) with >99% yields, whereas very good deprotecting yields (75-80%) were achieved for different acetylated β-glycopyranosides (galactose, ribofuranose) under these mild conditions. This strategy was successfully extended to the fully O-selective deprotection of acetylated nucleosides where >99% yield was rapidly obtained. No selectivity was observed for the N-deacetylation in amino acids and peptides.
- Dunne, Anthony,Palomo, Jose M.
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p. 88974 - 88978
(2016/10/03)
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- Bisindolyl maleimide derivative and preparation method and application thereof
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The invention provides a bisindolyl maleimide derivative and a preparation method and application thereof. The bisindolyl maleimide derivative has an excellent alpha-glucosidase inhibition effect and can be used for preventing and treating diabetes.
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Paragraph 0752
(2017/01/02)
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- Bisindolylmaleimide derivative, and preparation method and use thereof
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The invention provides a bisindolylmaleimide derivative, and a preparation method and a use thereof. The bisindolylmaleimide derivative has a good tumor treatment effect, especially has a good treatment effect on some drug-resistant tumors, and can realize accurate treatment of the drug-resistant tumors.
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Paragraph 0754; 0755
(2017/04/03)
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- Reagent-Controlled Stereoselective Glycosylation
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Provided are methods for the efficient stereoselective formation of glycosidic bonds, without recourse to prosthetic or directing groups.
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Paragraph 0320
(2015/02/19)
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- Direct C-H Trifluoromethylation of Glycals by Photoredox Catalysis
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A mild, efficient, and practical transformation for the direct C-H trifluoromethylation of glycals under visible light has been reported for the first time. This reaction employed fac-Ir3+(ppy)3 as the photocatalyst, Umemoto's reagent as the CF3 source, and a household blue LED or sunlight as the light source. Glycals bearing both electron-withdrawing and -donating protective groups performed this reaction smoothly. This visible light-mediated trifluoromethylation reaction was highlighted by the trifluoromethylation of the biologically important Neu2en moiety.
- Wang, Bang,Xiong, De-Cai,Ye, Xin-Shan
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p. 5698 - 5701
(2015/12/01)
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- Divergent synthesis of 2-C-branched pyranosides and oxepines from 1,2-gem-dibromocyclopropyl carbohydrates
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The ring opening of 1,2-(gem-dibromo)cyclopropyl carbohydrates by two different modes leads to either 2-C-(bromomethylene)pyranosides (using base) or 2-bromooxepines (using silver salts), as shown previously by us for a D-glucal-derived cyclopropane. The base-promoted ring opening is extended to encompass additional alcohol, thiol and amine nucleophiles, and diastereoisomeric cyclopropane precursors. Cross-coupling of the 2-C-(bromomethylene)pyranosides leads to extended 2-C-branched pyranosides. Silver-promoted ring expansion of the cyclopropyl carbohydrates in the presence of various alcohols is described. Cross-coupling of the resulting benzyl 2-bromooxepines affords 2-C-substituted oxepines.
- Moore, Peter W.,Schuster, Julia K.,Hewitt, Russell J.,Stone, M. Rhia L.,Teesdale-Spittle, Paul H.,Harvey, Joanne E.
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supporting information
p. 7032 - 7043
(2015/02/19)
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- Oxidative heck reaction of glycals and aryl hydrazines: A palladium-catalyzed C-glycosylation
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An efficient Heck-type C-glycosylation of glycals via the C-N bond cleavage of aryl hydrazines has been developed. The flexibility of the reaction was tested by the substrate scope, consisting of glycals from different carbohydrate origins as well as aryl hydrazines with various substituents. Pure α-C-glycosides were obtained when (3R)-glycals were employed, whereas α,β mixtures were observed with (3S)-glycals.
- Bai, Yaguang,Kim, Le Mai Hoang,Liao, Hongze,Liu, Xue-Wei
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supporting information
p. 8821 - 8825
(2013/09/24)
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- Synthesis of (-)-muricatacin from tri- O -acetyl- d -glucal
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The total synthesis of (-)-muricatacin is achieved using commercially available tri-O-acetyl-d-glucal as the starting material. The structure of the intermediate chiral butenolide is established unambiguously by X-ray crystallographic analysis, which consequently leads to correction of a previous structural misassignment. Georg Thieme Verlag Stuttgart. New York.
- González, Maria,Gándara, Zoila,Pazos, Gonzalo,Gómez, Generosa,Fall, Yagamare
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supporting information
p. 625 - 632
(2013/04/10)
-
- Pd-catalyzed allylic alkylation cascade with dihydropyrans: Regioselective synthesis of furo[3,2- c ]pyrans
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A regioselective palladium-catalyzed allylic alkylation cascade forms furo[3,2-c]pyrans from various cyclic β-dicarbonyl bis-nucleophiles and 3,6-dihydro-2H-pyran bis-electrophiles. The combination of allylic carbonate and anomeric siloxy leaving groups in the dihydropyran substrate allows control of the many regiochemical possibilities in this reaction. Annulation proceeds stereoconvergently to give cis-fused furopyrans from either cis- or trans-substituted starting material.
- Bartlett, Mark J.,Turner, Claire A.,Harvey, Joanne E.
-
supporting information
p. 2430 - 2433
(2013/07/05)
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- EFFICIENT AND SCALABLE PROCESS FOR THE MANUFACTURE OF FONDAPARINUX SODIUM
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The present invention relates to a process for the synthesis of the Factor Xa anticoagulent Fondaparinux and related compounds. The invention relates, in addition, to efficient and scalable processes for the synthesis of various intermediates useful in the synthesis of Fondaparinux and related compounds.
- -
-
Page/Page column 27
(2012/05/20)
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- Synthesis and antifungal properties of papulacandin derivatives
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Derivatives of an antifungal agent that targets the β-(1,3)-D-glucan synthase, papulacandin D, were synthesized and tested for activity. The papulacandin D structure contains a challenging benzannulated spiroketal unit, which is introduced in a palladiumcatalyzed cross-coupling reaction of a glycal silanolate and an aryl iodide followed by an oxidative spiroketalization. Four different variants were made, differing in the nature of the acyl side chain with respect to the length, and in the number and stereochemistry of the double bonds. Moderate biological activity was observed for the derivatives with a side chain based on palmitic acid and linoleic acid.
- Van Der Kaaden, Marjolein,Breukink, Eefjan,Pieters, Roland J.
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supporting information; experimental part
p. 732 - 737
(2012/07/14)
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- N-heterocyclic carbene catalyzed C-glycosylation: A concise approach from stetter reaction
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Described herein is the first example of an organocatalytic approach for acylanion addition to the anomeric carbon of 2-nitroglucal using an N-heterocyclic carbene catalyst. Control over the reaction conditions gives β-selective and nitro-eliminated C-glycosides, providing opportunities to produce new classes of C-glycoside.
- Vedachalam, Seenuvasan,Tan, Shi Min,Teo, Hui Ping,Cai, Shuting,Liu, Xue-Wei
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supporting information; experimental part
p. 174 - 177
(2012/02/16)
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- Synthesis and preliminary biological evaluation of carba analogues from Neisseria meningitidis A capsular polysaccharide
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The Gram-negative encapsulated bacterium Neisseria meningitidis type A (MenA) is a major cause of meningitis in developing countries, especially in the sub-Saharan region of Africa. The development and manufacture of an efficient glycoconjugate vaccine ag
- Gao, Qi,Zaccaria, Cristina,Tontini, Marta,Poletti, Laura,Costantino, Paolo,Lay, Luigi
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scheme or table
p. 6673 - 6681
(2012/09/22)
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- Tuning the leaving group in 2-deoxy-2-fluoroglucoside results in improved activity-based retaining β-glucosidase probes
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The potency of 2-deoxy-2-fluoroglycosides in activity-based profiling of human acid β-glucosidase is drastically improved by introducing an N-phenyl trifluoroacetimidate leaving group at the anomeric center. Protonation by the general acid-base catalyst i
- Walvoort, Marthe T. C.,Willems, Lianne I.,Witte, Martin D.,Van Der Marel, Gijsbert A.,Codee, Jeroen D. C.,Overkleeft, Herman S.,Kallemeijn, Wouter W.,Aerts, Johannes M. F. G.
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supporting information
p. 10386 - 10388,3
(2012/12/11)
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- Tuning the leaving group in 2-deoxy-2-fluoroglucoside results in improved activity-based retaining β-glucosidase probes
-
The potency of 2-deoxy-2-fluoroglycosides in activity-based profiling of human acid β-glucosidase is drastically improved by introducing an N-phenyl trifluoroacetimidate leaving group at the anomeric center. Protonation by the general acid-base catalyst i
- Walvoort, Marthe T. C.,Kallemeijn, Wouter W.,Willems, Lianne I.,Witte, Martin D.,Aerts, Johannes M. F. G.,Van Der Marel, Gijsbert A.,Codee, Jeroen D. C.,Overkleeft, Herman S.
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supporting information
p. 10386 - 10388
(2013/01/14)
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- Probing myo-inositol 1-phosphate synthase with multisubstrate adducts
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The synthesis of a series of carbohydrate-nucleotide hybrids, designed to be multisubstrate adducts mimicking myo-inositol 1-phosphate synthase first oxidative transition state, is reported. Their ability to inhibit the synthase has been assessed and resu
- Deranieh, Rania M.,Greenberg, Miriam L.,Le Calvez, Pierre-B.,Mooney, Maura C.,Migaud, Marie E.
-
supporting information
p. 9601 - 9619
(2013/01/16)
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- Fluorine-directed β-galactosylation: Chemical glycosylation development by molecular editing
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Validation of the 2-fluoro substituent as an inert steering group to control chemical glycosylation is presented. A molecular editing study has revealed that the exceptional levels of diastereocontrol in glycosylation processes by using 2-fluoro-3,4,6-tri-O-benzyl glucopyranosyl trichloroacetimidate (TCA) scaffolds are a consequence of the 2R,3S,4S stereotriad. This study has also revealed that epimerization at C4, results in a substantial enhancement in β-selectivity (up to β/α 300:1). Copyright
- Durantie, Estelle,Bucher, Christoph,Gilmour, Ryan
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p. 8208 - 8215
(2012/08/27)
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- Stereoelectronic factors in the stereoselective epoxidation of glycals and 4-deoxypentenosides
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Glycals and 4-deoxypentenosides (4-DPs), unsaturated pyranosides with similar structures and reactivity profiles, can exhibit a high degree of stereoselectivity upon epoxidation with dimethyldioxirane (DMDO). In most cases, the glycals and their corresponding 4-DP isosteres share the same facioselectivity, implying that the pyran substituents are largely responsible for the stereodirecting effect. Fully substituted dihydropyrans are subject to a "majority rule", in which the epoxidation is directed toward the face opposite to two of the three groups. Removing one of the substituents has a variable effect on the epoxidation outcome, depending on its position and also on the relative stereochemistry of the remaining two groups. Overall, we observe that the greatest loss in facioselectivity for glycals and 4-DPs is caused by removal of the C3 oxygen, followed by the C5/anomeric substituent, and least of all by the C4/C2 oxygen. DFT calculations based on polarized-π frontier molecular orbital (PPFMO) theory support a stereoelectronic role for the oxygen substituents in 4-DP facioselectivity, but less clearly so in the case of glycals. We conclude that the anomeric oxygen in 4-DPs contributes toward a stereoelectronic bias in facioselectivity whereas the C5 alkoxymethyl in glycals imparts a steric bias, which at times can compete with the stereodirecting effects from the other oxygen substituents.
- Alberch, Laura,Cheng, Gang,Seo, Seung-Kee,Li, Xuehua,Boulineau, Fabien P.,Wei, Alexander
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scheme or table
p. 2532 - 2547
(2011/06/19)
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- Palladium-catalyzed direct cross-coupling reaction of glycals with activated alkenes
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An efficient method for a Pd(OAc)2-catalyzed cross-coupling reaction of glycals with activated alkenes under mild conditions has been developed. This transformation provides an expedient synthetic method to C(2)-functionalized glycals, which ar
- Bai, Yaguang,Zeng, Jing,Cai, Shuting,Liu, Xue-Wei
-
supporting information; experimental part
p. 4394 - 4397
(2011/10/09)
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- Study of kaempferol glycoside as an insulin mimic reveals glycon to be the key active structure
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Diabetes mellitus is increasing in prevalence with patient numbers rising throughout the world. Current treatments for diabetes mellitus focus on control of blood glucose levels. Certain kinds of flavonoids or their glycosides stimulate cells to improve glucose uptake and lower blood glucose levels. We synthesized kaempferol 3-O-neohesperidoside (1), a naturally occurring substance present in Cyathea phalerata Mart., reported to mimic the action of insulin. Synthetic 1 promoted glucose uptake in the cultured cell line, L6. Further studies to determine the core structure responsible for this activity using synthetic compounds revealed neohesperidose to be the primary pharmacophore. These findings support the use of certain saccharides as a potential novel treatment for diabetes mellitus by replacing or supporting insulin.
- Yamasaki, Kazuaki,Hishiki, Ryogo,Kato, Eisuke,Kawabata, Jun
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supporting information; experimental part
p. 17 - 21
(2011/04/17)
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- Developing a diastereoselective intramolecular [4 + 3] cycloaddition of nitrogen-stabilized oxyallyl cations derived from N-sulfonyl-substituted allenamides
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Efforts toward achieving a practical and diastereoselective intramolecular [4 + 3] cycloaddition of nitrogen-stabilized oxyallyl cations with tethered dienes are described. Epoxidation of N-sulfonyl substituted allenamides with dimethyldioxirane (DMDO) generates nitrogen-stabilized oxyallyl cations that readily undergo stereoselective [4 + 3] cycloaddition with dienes. Selectivity is found to depend on the tethering length as well as the stability of the oxyallyl cation intermediate, whether generated from N-carbamoyl- or N-sulfonyl-substituted allenamides. The use of chiral N-sulfonyl-substituted allenamides provided minimal diastereoselectivity in the cycloaddition, while high diastereoselectivity can be achieved with a stereocenter present on the tether. These studies provide further support for the synthetic utility of allenamides.
- Lohse, Andrew G.,Hsung, Richard P.,Leider, Mitchell D.,Ghosh, Sunil K.
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scheme or table
p. 3246 - 3257
(2011/07/09)
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- Total synthesis of landomycin A, a potent antitumor angucycline antibiotic
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The first total synthesis of landomycin A, the longest and most potent antitumor angucycline antibiotic, has been achieved in 63 steps and 0.34% overall yield starting from 2,5-dihydroxybenzoic acid, 3,5-dimethylphenol, triacetyl d-glucal, and d-xylose, with a convergent linear sequence of 21 steps.
- Yang, Xiaoyu,Fu, Boqiao,Yu, Biao
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supporting information; experimental part
p. 12433 - 12435
(2011/10/02)
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- A fluoro analogue of UDP-α-d-glucuronic acid is an inhibitor of UDP-α-d-apiose/UDP-α-d-xylose synthase
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UDP-2F-glucuronic acid was synthesized and analyzed as a mechanistic probe to investigate the ring contraction step catalyzed by UDP-d-apiose/UDP-d-xylose synthase (AXS). The Royal Society of Chemistry 2011.
- Choi, Sei-Hyun,Ruszczycky, Mark W.,Zhang, Hua,Liu, Hung-Wen
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scheme or table
p. 10130 - 10132
(2011/10/31)
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- Formal synthesis of aspergillide A from tri-O-acetyl-d-glucal
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We describe an efficient synthesis of a key intermediate in the synthesis of aspergillide A from a commercially available, chiral starting material. Georg Thieme Verlag Stuttgart · New York.
- Zuniga, Andrea,Perez, Manuel,Gonzalez, Maria,Gomez, Generosa,Fall, Yagamare
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experimental part
p. 3301 - 3306
(2011/11/30)
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- Synthesis of - C -glycosides by samarium diiodide mediated coupling of glycosyl pyridyl sulfones with alkenes
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A mild method for the synthesis of -C-glycosides by the samarium diiodide mediated coupling reactions of glycosyl 2-pyridyl sulfones with different ,-unsaturated carbonyl compounds has been developed. This method allows the use of less amount of substrates. Georg Thieme Verlag Stuttgart - New York.
- Li, Gen,Xiong, De-Cai,Ye, Xin-Shan
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scheme or table
p. 2410 - 2414
(2011/11/04)
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- A novel glycosyl donor for synthesis of 2-acetamido-4-amino-2,4,6-trideoxy- α-d-galactopyranosides
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2-Azido-4-benzylamino-4-N-,3-O-carbonyl-2,4,6-trideoxy-d-galactopyranosyl trichloroacetimidate (14) was conveniently prepared in six steps by regioselective introduction of an N-benzyl carbamate at O-3 of 6-deoxy-d-glucal 6, followed by mesylation at O-4.
- Iynkkaran, Ithayavani,Bundle, David R.
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scheme or table
p. 2323 - 2327
(2010/12/24)
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- Erosion of stereochemical control with increasing nucleophilicity: O-glycosylation at the diffusion limit
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(Chemical Equation Presented) Nucleophilic substitution reactions of 2-deoxyglycosyl donors indicated that the reactivity of the oxygen nucleophile has a significant impact on stereoselectivity. Employing ethanol as the nucleophile resulted in a 1:1 (α:β) ratio of diastereomers under SN1-like reaction conditions. Stereoselective formation of the 2-deoxy-α-O-glycoside was only observed when weaker nucleophiles, such as trifluoroethanol, were employed. The lack of stereoselectivity observed in reactions of common oxygen nucleophiles can be attributed to reaction rates of the stereochemistry-determining step that approach the diffusion limit. In this scenario, both faces of the prochiral oxocarbenium ion are subject to nucleophilic addition to afford a statistical mixture of diastereomeric products. Control experiments confirmed that all nucleophilic substitution reactions were performed under kinetic control.
- Beaver, Matthew G.,Woerpel
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supporting information; experimental part
p. 1107 - 1118
(2010/04/06)
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- Fluorine-directed glycosylation
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Everything's under control: A stabilizing fluorine electrostatic interaction has been exploited to control oxonium ion conformation in 2-fluoropyranose derivatives (see scheme). When matched with the inductive nature of the protecting groups, the glycosyl
- Bucher, Christoph,Gilmour, Ryan
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supporting information; experimental part
p. 8724 - 8728
(2011/01/06)
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- Anticancer agents from the Australian tropical rainforest: Spiroacetals EBC-23, 24, 25, 72, 73, 75 and 76
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EBC-23, 24, 25, 72, 73, 75 and 76 were isolated from the fruit of Cinnamomum laubatii (family Lauraceae) in the Australian tropical rainforests. EBC-23 (1) was synthesized stereoselectively, in nine linear steps in 8% overall yield, to confirm the reported relative stereochemistry and determine the absolute stereochemistry. Key to the total synthesis was a series of Tietze - Smith linchpin reactions. The novel spiroacetal structural motif, exemplified by EBC-23 (1), was found to inhibit the growth of the androgen-independent prostate tumor cell line DU145 in the mouse model, indicating potential for the treatment of refractory solid tumors in adults.
- Dong, Lin,Schill, Heiko,Grange, Rebecca L.,Porzelle, Achim,Johns, Jenny P.,Parsons, Peter G.,Gordon, Victoria A.,Reddell, Paul W.,Williams, Craig M.
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scheme or table
p. 11307 - 11318
(2010/05/02)
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- Synthesis of glycal-based chiral benzimidazoles by VO(acac) 2-CeCl3 combo catalyst and their self-aggregated nanostructured materials
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(Figure Presented) VO(acac)2-CeCl3 combo catalyst has been developed for chemoselective cyclocondensation cum oxidation under mild reaction conditions toward synthesis of a new class of optically pure compounds, 2-(2′-C-3′,4′,6′-tri-O-benzyl/methyl-glycal)-1H- benzimidazoles. It involves an operationally simple synthetic protocol efficient for the syntheses of a wide range of chiral benzimidazoles in high yields without formation of undesired 1,2-disubstituted and pseudoglycal byproducts. Vanadium(V) is found as active oxidant for the chemical processes which is investigated by UV absorption spectroscopy. Highly ordered one-dimensional low molecular mass organic nanostructured materials are fabricated by nanocrystallization of the chiral nanoscale building blocks. Theoretical calculation by the B3LYP/6-31G** level of theory of the glycal-based chiral benzimidazoles shows out of planar geometry of the 1H-anthra[1,2-d] imidazole-6,11-dione moiety, which is responsible for the strong self-aggregation to generate ultralong nanostructured materials. We have also found nice agreement between the theoretical results with the experimental observation in 2D-NOESY experiments. The photophysical property of the solid nanostructured materials is also reported. 2009 American Chemical Society.
- Maiti, Dilip K.,Halder, Samiran,Pandit, Palash,Chatterjee, Nirbhik,De Joarder, Dripta,Pramanik, Nabyendu,Saima, Yasmin,Patra, Amarendra,Maiti, Prabir K.
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supporting information; experimental part
p. 8086 - 8097
(2010/02/28)
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- A new, enantioselective synthesis of (+)-isolaurepan
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A highly enantioselective synthesis of 2,6-syn-disubstituted tetrahydropyrans from commercially available tri-O-acetyl-d-glucal, based on a thermal Claisen rearrangement, allows enantioselective synthesis of (+)-isolaurepan when combined with a ring expan
- Pazos, Gonzalo,Pérez, Manuel,Gándara, Zoila,Gómez, Generosa,Fall, Yagamare
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supporting information; experimental part
p. 5285 - 5287
(2009/12/26)
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- Microwave-assisted stereoselective α-2-deoxyglycosylation of hex-1-en-3-uloses
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α-2-Deoxyglycosides were successfully synthesized by means of microwave-assisted glycosylation. Hex-1-en-3-uloses were treated with a catalytic amount of AlCl3 and various O-nucleophiles including alcohols and sugars under microwave conditions.
- Lin, Hui-Chang,Wu, Hsu-Hsuan,Lin, Zi-Ping,Lin, Chih-Yuan,Lin, Chun-Hung,Chen, Kun-Lung,Wong, Fung Fuh
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body text
p. 7327 - 7329
(2010/02/28)
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- Regio- and stereo-selective synthesis of aryl 2-deoxy-C-glycopyranosides by palladium-catalyzed Heck coupling reactions of glycals and aryl iodides
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The Heck coupling of aryl iodides with pyranoid glycals using a catalytic amount of Pd(OAc)2 to form pyranoid aryl C-glycosides has been achieved. The reaction takes place smoothly in the presence of Ag 2CO3 and Cu(OAc)2 (or DMSO) in acetonitrile. This arylation process, which occurs in a highly regio- and stereo-selective manner, provides a simple, mild, and efficient approach to the synthesis of aryl 2-deoxy-C-glycopyranosides.
- Li, Hou-Hua,Ye, Xin-Shan
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experimental part
p. 3855 - 3861
(2009/10/23)
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