- [2+2] Photoadditions with chiral 2,5-cyclohexadienone synthons
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Three chiral 2,5-cyclohexadienone synthons bearing different chiral auxiliaries were examined in [2+2] photoadditions with cyclopentene. Regeneration of the 'masked' double bond in the adducts resulted in the preparation of optically active 5-4-6 adducts. The enantiomeric purity of each adduct was found to be >95% using comparative 13C NMR analysis of the appropriate ketals. The asymmetry induced in the cycloaddition step of our methodology indicated that the facial selectivity was directly correlated to the degree of steric bulk of the chiral auxiliary on the synthon.
- Lange, Gordon L.,Humber, Craig C.,Manthorpe, Jeffrey M.
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Read Online
- Parallel synthesis and biological evolution of quinic acid derivatives as immuno-suppressing agents against T-cell receptors
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A simple protocol for the synthesis of quinic acid derivatives was established and their biological evolution against T-cells is studied. Results showed that one of the derivatives, Cyn-1324, has low toxicity on T-cells and a high effect on reducing Signal 2 of T-cell immune responses. In vitro binding measurements of atomic force spectroscopy further indicated that the blocking effect of Cyn-1324 between CD28 and CD80 was about 31 ± 4%. In vivo animal tests also confirmed that Cyn-1324 can reduce the allergic responses from ovalbumin-induced mice with little toxicity. Based on these observations, Cyn-1324 can be a mild immuno-suppressive candidate for future drug development.
- Huang, Chih-Yu,Chen, Li-Hsun,Huang, Hsuan-Yu,Kao, Feng-Sheng,Lee, Yun-Ta,Selvaraju, Manikandan,Sun, Chung-Ming,Chen, Hueih-Min
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Read Online
- Asymmetric Total Synthesis of (-)-Guignardones A and B
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The asymmetric total synthesis of (-)-guignardones A (2) and B (1) has been accomplished. The highly oxidized 6-oxabicyclo[3.2.1]octane core was constructed from d-quinic acid via substitution/desulfurization reaction with thiophenol to forge the bridged ring scaffold, and a Pummerer rearrangement and 1,4-addition/elimination sequence was employed to install the β-carbonyl group at the congested C-1 position. A late-stage Knoevenagel condensation-6π-electrocyclization and directed hydrogenation formed (-)-guignardone B (1), which was subjected to dehydration to furnish (-)-guignardone A (2).
- Gong, Jianxian,Yan, Zhiming,Yang, Zhen,Zhao, Chunbo
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Read Online
- Facile synthesis of the cyclohexane fragment of enacloxins, a series of antibiotics isolated from Frateuria sp. W-315
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An efficient and good yield synthesis of the cyclohexane moiety of enacyloxins, a series of antibiotics isolated from Frateuria sp. W-315, was achieved from D-quinic acid using a successive Barton - McCombie deoxygenation.
- Saito, Aki,Igarashi, Wataru,Furukawa, Hiroyuki,Yamada, Teiko,Kuwahara, Shigefumi,Kiyota, Hiromasa
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Read Online
- Total syntheses of aminomethyl-C-dideoxyglycopyranosides and their quinamides
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Lewis acid promoted cyclization of homoallylic alcohol 1 with acetal 2 gave 4-chloro-2-phthalimidomethyl-6-methyltetrahydropyrans. Their dehydrochlorination produced two regioisomeric dihydropyrans. Subsequent cis- and trans-dihydroxylation gave four race
- Gremyachinskiy, Dmitriy E.,Samoshin, Vyacheslav V.,Gross, Paul H.
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Read Online
- Sulfamate-tethered aza-Wacker approach towards analogs of Bactobolin A
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Here, we describe an approach towards analogs of the potent antibiotic Bactobolin A. Sulfamate-tethered aza-Wacker cyclization reactions furnish key synthons, which we envision can be elaborated into analogs of Bactobolin A. Docking studies show that the
- Nagamalla, Someshwar,Johnson, David K.,Sathyamoorthi, Shyam
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p. 1348 - 1357
(2021/04/09)
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- Synthetic Studies of the Rubellin Natural Products: Development of a Stereoselective Strategy and Total Synthesis of (+)-Rubellin C
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This manuscript describes our studies of the class of natural products known as the rubellins, culminating in the total synthesis of (+)-rubellin C. These anthraquinone-based natural products contain a variety of stereochemical and architectural motifs, including a 6-5-6-fused ring system, 5 stereogenic centers, and a central quaternary center. Herein, we report our development of a strategy to target the stereochemically dense core and anthraquinone nucleus, including approaches such as a bifunctional allylboron and vinyl triflate reagent, an anthraquinone benzylic metalation strategy, and a late-stage anthraquinone introduction strategy. Our studies culminate in a successful route to highly functionalized anthraquinone-based natural product scaffolds and a stereoselective total synthesis of (+)-rubellin C. These strategies and outcomes will aid in synthetic planning toward anthraquinone-based natural products of high interest.
- Gartman, Jackson A.,Tambar, Uttam K.
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p. 11237 - 11262
(2021/08/16)
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- A concise synthesis of carbasugars isolated from Streptomyces lincolnensis
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(?)-Quinic acid was used as a starting material in the hemisynthesis of two epimeric carbasugars isolated from Streptomyces lincolnensis. Previous 10–12 steps syntheses for the carbasugars have been herein shortened to 4–6 steps by using quinic acid as a
- Holmstedt, Suvi,Candeias, Nuno R.
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- Total Synthesis of (+)-Rubellin C
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The rubellins are a family of stereochemically complex anthraquinoid heterodimers containing an unprecedented chemical scaffold. Although the rubellins have been known for over three decades, no total synthesis has been achieved since their discovery. The
- Gartman, Jackson A.,Tambar, Uttam K.
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supporting information
p. 9145 - 9150
(2020/08/24)
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- Process for synthesizing oseltamivir sulfonate from quinic acid
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The invention discloses a process for synthesizing oseltamivir sulfonate from quinic acid. The process specifically comprises the following steps of: S1, adding quinic acid and ethyl acetate into a round-bottom flask, and adding p-toluenesulfonic acid and 2, 2-dimethoxypropane, carrying out reaction to obtain a brown solid 2; S2, adding the brown solid 2 and dichloromethane into the round-bottom flask, dropwise adding methanesulfonyl chloride and triethylamine into the round-bottom flask while performing stirring, and carrying out reaction to obtain an intermediate 3; S3, adding the obtained intermediate 3 into a three-neck flask, adding ethanol and sodium ethoxide for reaction, and removing the dichloromethane after finishing the reaction to obtain an intermediate 4; and S4, adding the intermediate 4 and dichloromethane into the round-bottom flask, dropwise adding the methanesulfonyl chloride and triethylamine into the round-bottom flask while performing stirring, extracting a reaction solution with dichloromethane and water after finishing the reaction, concentrating an obtained organic phase under reduced pressure, adding methanol for crystallization, and performing filtering toobtain a white crystal 5, namely oseltamivir sulfonate.
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Paragraph 0009; 0023-0025; 0033-0035; 0043-0045
(2021/01/04)
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- Gold(I)-Catalyzed Intramolecular Hydroamination and Hydroalkoxylation of Alkynes: Access to Original Heterospirocycles
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We report here a simple and robust gold-catalyzed annulation reaction, giving N- and O-spirocycles in good to excellent yields. We have prepared a library of protected amines and tertiary alcohols that give, upon cyclization with alkynes, a representative set of heterospirocycles and illustrate reaction compatibility with diverse functional groups. A change in catalytic activity is possible by modifying the solvent, and two original tricyclic spirocycles were synthesized in a tandem reaction.
- Soklou, Kossi Efouako,Marzag, Hamid,Bouillon, Jean-Philippe,Marchivie, Mathieu,Routier, Sylvain,Plé, Karen
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supporting information
p. 5973 - 5977
(2020/08/12)
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- Acrylate compound and application thereof
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The invention relates to an acrylate compound and an application of the acrylate compound to preparing a drug used for preventing or treating IL-17F related diseases or symptoms.
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Paragraph 0125; 0126; 0127; 0128
(2018/09/21)
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- ANTIMICROBIAL AGENTS
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The invention provides novel analogues of enacyloxin Ha and their pharmaceutically acceptable salts, metabolites, isomers (e.g. stereoisomers) and prodrugs. Such compounds are effective in the treatment of infections caused by Gram-negative bacteria such as Acinetobacter baumannii. Compounds in accordance with the invention include those of formula (A), and their pharmaceutically acceptable salts, metabolites, isomers (e.g. stereoisomers) and prodrugs: In formula (A): X is 0 or NRx (where R* is either H or C1-3 alkyl, e.g. CH3); R1 is a 5- or 6-membered, saturated or unsaturated, carbocyclic ring optionally substituted by one or more substituents, or R1 is an optionally substituted straight-chained or branched C-1-6 alkyl group (e.g. C1-3 alkyl group); R2 is H, F, CI, Br, I or CH3; R3 is H or OH; R8 is a straight-chained or branched C1-8 alkyl group (e.g. a C1-6 aikyl group); Y is one of the following groups: (wherein each * denotes the point of attachment of the group to the remainder of the molecule; R9 is H, F, CI, Br or I; R4 and R5 are independently selected from H and OH, or R4 and R5 together are =0, preferably R4 is H and R5 is OH; R6 is H, F, CI, Br, I or CH3; R7 is H and R7' is OH, or R7 and R7' together are =0, preferably R7 is H and R7' is OH); and each— independently represents an optional bond (i.e. each of C2-C3, C4-C5, C6-C7, C8-C9 and C10-C11 are independently either C-C (single) or C=C (double) bonds).
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Page/Page column 48
(2018/11/22)
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- 1 - O - dicafeoyl quininic acid, its derivatives, preparation method and use thereof (by machine translation)
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The invention of the formula (II) as shown by a 1 - O - caffenoylquinate acid derivatives, and 1 - O - dicafeoyl quininic acid, of formula (II) as shown by a 1 - O - caffenoylquinate acid derivatives and its application of salt. 1 - O - dicafeoyl quininic acid, of formula (II) as shown by a 1 - O - caffenoylquinate acid derivatives and the salts thereof inhibit interleukin 17, in particular interleukin 17 F of secretion, and capable of preventing and treating the tumor. Experimental results show that, 1 - O - dicafeoyl quininic acid concentration is 0.5 μm/L when the interleukin 17 F inhibition rate of close to 70%; 1 - O - dicafeoyl quininic acid in 20 mg/kg at a dose to the melanoma, pancreatic cancer, colorectal cancer, lung cancer tumor has good inhibition effect, are more than 50%, and its derivatives black pigment lump, pancreatic cancer, colorectal cancer, lung cancer tumor also has better inhibition effect. (by machine translation)
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Paragraph 0116; 0117; 0120; 0121
(2018/06/16)
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- Stereoselective Synthesis and Evaluation of C6-Substituted 5a-Carbasugar Analogues of SL0101 as Inhibitors of RSK1/2
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A convergent synthesis of 5a-carbasugar analogues of the n-Pr-variant of SL0101 is described. The analogues were synthesized in an effort to find compounds with potent in vivo efficacy in the inhibition of p90 ribosomal s6 kinase (RSK1/2). The synthesis derived the desired C-4 L-rhamnose stereochemistry from quinic acid and used a highly selective cuprate addition, NaBH4 reduction, Mitsunobu inversion, and alkene dihydroxylation to install the remaining stereochemistry. A Pd-catalyzed cyclitolization stereoselectively installed the aglycon at the anomeric position. The analogues were evaluated as RSK1/2 inhibitors and found to have 3- to 6-fold improved activity.
- Li, Mingzong,Li, Yu,Ludwik, Katarzyna A.,Sandusky, Zachary M.,Lannigan, Deborah A.,O’Doherty, George A.
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supporting information
p. 2410 - 2413
(2017/05/12)
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- Synthesis of p-coumaroylquinic acids and analysis of their interconversion
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The synthesis of four isomers of p-coumaroylquinic acids was performed by esterification of p-acetylcoumaroylchloride with a suitably protected (?)-quinic acid. All isomers have been characterized by means of NMR spectroscopy and circular dichroism. Acyl migration was observed in the synthesis of 3-O-p-coumaroylquinic acid and 4-O-p-coumaroylquinic acid. Calculations on the most stable conformations of all isomers have also been performed to explain the acyl migration observed during the synthesis procedure.
- Gutiérrez Ortiz, Anggy Lusanna,Berti, Federico,Navarini, Luciano,Monteiro, Angelo,Resmini, Marina,Forzato, Cristina
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p. 419 - 427
(2017/03/23)
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- Novel compound, its synthetic method and therapeutic use (by machine translation)
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Novel compounds are described. The compounds generally comprise an acidic group, a basic group, a substituted amino or N-acyl and a group having an optionally hydroxylated alkane moiety. Pharmaceutical compositions comprising the inhibitors of the invention are also described. Methods of inhibiting neuraminidase in samples suspected of containing neuraminidase are also described. Antigenic materials, polymers, antibodies, conjugates of the compounds of the invention with labels, and assay methods for detecting neuraminidase activity are also described.
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Paragraph 2316-2322
(2016/10/07)
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- METHOD FOR MANUFACTURING 3,4,5-TRICAFFEOYLQUINIC ACID
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Provided are a method for manufacturing 3,4,5-tricaffeoylquinic acid, which can produce 3,4,5-tricaffeoylquinic acid with high efficiency by a simple operation in a short process using inexpensive raw materials, and intermediate compounds. The method for manufacturing 3,4,5-tricaffeoylquinic acid of the invention includes at least Step (1) of allowing a compound represented by Formula (1) or a compound represented by Formula (2) to react with a compound represented by Formula (4); and Step (2) of deprotecting the product obtained in Step (1), and producing 3,4,5-tricaffeoylquinic acid:
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Paragraph 0325; 0326
(2016/02/19)
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- METHOD FOR PRODUCING 3,4,5-TRICAFFEOYLQUINIC ACID
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PROBLEM TO BE SOLVED: To provide a method for producing 3,4,5-tricaffeoylquinic acid capable of efficiently producing 3,4,5-tricaffeoylquinic acid in a short process by a simple operation. SOLUTION: Provided is a method for producing 3,4,5-tricaffeoylquin
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Paragraph 0078; 0079
(2017/03/17)
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- Further study on synthesis of the cyclobakuchiols
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Abstract Two results are described. First, quinic acid was transformed into the monoacetate of 2-cyclohexene-1,4-diol. The Ni-catalyzed allylic substitution of the monoacetate with CH2C(Me)MgBr/ZnCl2/TMEDA followed by oxidation of th
- Kawashima, Hidehisa,Sakai, Masahiro,Kaneko, Yuki,Kobayashi, Yuichi
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p. 2387 - 2392
(2015/03/30)
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- Interaction of chlorogenic acids and quinides from coffee with human serum albumin
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Chlorogenic acids and their derivatives are abundant in coffee and their composition changes between coffee species. Human serum albumin (HSA) interacts with this family of compounds with high affinity. We have studied by fluorescence spectroscopy the spe
- Sinisi, Valentina,Forzato, Cristina,Cefarin, Nicola,Navarini, Luciano,Berti, Federico
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p. 332 - 340
(2014/08/18)
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- Interaction of chlorogenic acids and quinides from coffee with human serum albumin
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Chlorogenic acids and their derivatives are abundant in coffee and their composition changes between coffee species. Human serum albumin (HSA) interacts with this family of compounds with high affinity. We have studied by fluorescence spectroscopy the spe
- Sinisi, Valentina,Forzato, Cristina,Cefarin, Nicola,Navarini, Luciano,Berti, Federico
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p. 332 - 340
(2015/01/30)
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- METHOD FOR PREVENTING OR TREATING ARRHYTHMIA, METHOD FOR PREVENTING OR TREATING ATRIAL FIBRILLATION, MODEL OF SUSTAINED ATRIAL FIBRILLATION, METHOD FOR PRODUCING THE MODEL, AND METHOD FOR SCREENING FOR ATRIAL FIBRILLATION INHIBITOR
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A method for preventing or treating atrial fibrillation, including: administering, to an individual, an atrial fibrillation inhibitor containing a compound expressed by one of the following Structural Formulas (I) to (VI) or a pharmacologically acceptable salt thereof: where in the Structural Formula (III), Gluc refers to glucuronic acid,
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Paragraph 0091
(2014/03/24)
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- Syntheses of 3-, 4-, and 5-O-feruloylquinic acids
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The efficient synthesis of 3-, 4-, and 5-O-feruloylquinic acids starting from d-(-)-quinic acid is described. Esterification of suitably protected quinic acid derivatives with 3-(4-acetoxy-3-methoxyphenyl)-acryloyl chloride and subsequent hydrolysis of al
- Dokli, Irena,Navarini, Luciano,Hamersak, Zdenko
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p. 785 - 790
(2013/08/23)
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- Design, synthesis, biological evaluation, and modeling of a non-carbohydrate antagonist of the myelin-associated glycoprotein
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Broad modifications of various positions of the minimal natural epitope recognized by the myelin-associated glycoprotein (MAG), a blocker of regeneration of neurite injuries, produced sialosides with nanomolar affinities. However, important pharmacokineti
- Schwardt, Oliver,Koliwer-Brandl, Hendrik,Zimmerli, Raphael,Mesch, Stefanie,Rossato, Gianluca,Spreafico, Morena,Vedani, Angelo,Kelm, S?rge,Ernst, Beat
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experimental part
p. 7239 - 7251
(2010/12/20)
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- ANTI-INFLAMMATORY QUINIC ACID DERIVATIVES FOR ORAL ADMINISTRATION
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Disclosed are compounds comprising analogs of quinic acids or shikimic acids having anti-inflammatory properties. The compounds are suitable for oral administration, stable, and demonstrate significant efficacy in inhibiting NF-kB, inhibiting leukocyte ad
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Page/Page column 14
(2009/06/27)
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- Stereoselective synthesis of novel cyclic γ-amino acids and triazole derivatives
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Four polyhydroxylated γ-azido and three γ-amino acids 1-4 have been synthesized from (-)-quinic acid. The nitrogen functionality in the reported derivatives was introduced through regioselective ring-opening of cyclic sulfates with azide anion. The synthesis of the 4- and 5-epimers of γ-azido acid 1a - derivatives 2 and 3a, respectively - was achieved by regioselective oxidation of dibutylstannylene acetals derived from 1,2-diols, followed by diastereoselective reduction of their corresponding α-hydroxy ketones. The presence of the azide functional group in the reported γ-azido acids was exploited to permit interlinking of bioactive molecular entities. Wiley-VCH Verlag GmbH & Co. KGaA, 2008.
- Prazeres, Veronica F. V.,Castedo, Luis,Gonzalez-Bello, Concepcion
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body text
p. 3991 - 4003
(2009/04/11)
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- Novel and efficient syntheses of (-)-methyl 4-epi-shikimate and 4,5-epoxy-quinic and -shikimic acid derivatives as key precursors to prepare new analogues
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We have developed simple methods that provide a rapid entry into the synthesis of a series of quinate and shikimate analogues, including (-)-methyl 4-epi-shikimate and the 4,5-epoxy analogues of the parent acids. Epoxy derivatives of quinic and shikimic a
- Sanchez-Abella, Laura,Fernandez, Susana,Armesto, Nuria,Ferrero, Miguel,Gotor, Vicente
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p. 5396 - 5399
(2007/10/03)
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- Synthesis of 25-hydroxy-19-norvitamin D3 analogs and their antiproliferative activities on prostate cells
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Synthesis of 25-hydroxy-19-norvitamin D3 derivatives as prohormone type agents for anti-prostate diseases was accomplished utilizing Julia-type olefination. Synthesized compounds showed potent antiproliferative activity on an immortalized norma
- Arai, Midori A.,Tsutsumi, Ryuji,Hara, Hideki,Chen, Tai C.,Sakaki, Toshiyuki,Urushino, Naoko,Inouye, Kuniyo,Kittaka, Atsushi
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p. 469 - 479
(2007/10/03)
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- Studies for the transformation of carbocycles into carbohydrates: Approach toward the synthesis of higher sugar derivatives
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A highly stereocontrolled synthesis of a β-D-ribo-hept-6- ulopyranosuronamide derivative, a useful intermediate for the synthesis of other higher sugars, has been developed using naturally occurring (-)-quinic acid as a chiral starting material. The trans
- Baptistella, Lucia Helena Brito,Cerchiaro, Giselle
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p. 665 - 671
(2007/10/03)
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- Neuraminidase inhibitors
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The present invention provides compounds of formula Ia and Ib or a pharmaceutically acceptable salt, prodrug, or ester thereof, useful in the inhibition of neuraminidase enzymes from disease-causing microorganisms, especially influenza neuraminidase, phar
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- Efficient synthesis of 2-modified 1α,25-dihydroxy-19-norvitamin D3 with Julia olefination: High potency in induction of differentiation on HL-60 cells
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Six novel 2-substituted analogues of 1α,25-dihydroxy-19-norvitamin D3, 6a,b-8a,b, were efficiently synthesized utilizing (-)-quinic acid as the A-ring precursor. The C2-modified A-rings were prepared as 4-alkylated (3R,5R)-3,5-dihydroxycyclohex
- Ono, Keiichiro,Yoshida, Akihiro,Saito, Nozomi,Fujishima, Toshie,Honzawa, Shinobu,Suhara, Yoshitomo,Kishimoto, Seishi,Sugiura, Takayuki,Waku, Keizo,Takayama, Hiroaki,Kittaka, Atsushi
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p. 7407 - 7415
(2007/10/03)
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- First efficient synthesis of chlorogenic acid
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The first efficient synthesis of chlorogenic acid (1) was achieved in four steps (three purifications) from quinic acid (2). The overall yield was 65%, The key intermediate was quinic acid bisacetonide (6), selectively prepared by a modified kinetic aceta
- Sefkow, Michael
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p. 1137 - 1141
(2007/10/03)
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- A Class of C2 and Pseudo C2 Symmetric Ketone Catalysts for Asymmetric Epoxidation. Conformational Effect on Catalysis
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A class of C2 and pseudo C2 symmetric ketones with one fused ring at each side of the carbonyl group have been prepared from quinic acid and found to be effective catalysts for the asymmetric epoxidation of a variety of olefins. Electron deficient olefins such as enones can be efficiently epoxidized. Encouragingly good enantioselectivity is also obtained for the epoxidation of styrenes. The studies show that the ketone conformation plays an important role in the reactivity and selectivity of the catalyst.
- Wang, Zhi-Xian,Miller, Susie M.,Anderson, Oren P.,Shi, Yian
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p. 6443 - 6458
(2007/10/03)
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- Industrial synthesis of the key precursor in the synthesis of the anti-influenza drug oseltamivir phosphate (Ro 64-0796/002, GS-4104-02): Ethyl (3R,4S,5S)-4,5-epoxy-3-(1-ethyl-propoxy)-cyclohex-1 -ene-1 -carboxylate
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Starting from (-)-quinic acid, the title compound was synthesized in seven chemical steps and an overall yield of 35-38%. The route of the improved Gilead synthesis was not changed. However, significant improvements in each step led to a doubled overall yield, a 30% reduction in the number of unit operations, and an excellent quality (≥99%) of the resulting epoxide. A highly regioselective method for the dehydration of a quinic acid to a shikimic acid derivative and for the reduction of a cyclic ketal was found. Alternatively, the title compound was synthesized in six chemical steps and 63-65% yield from commercially available (-)-shikimic acid. Compared to the optimized quinic acid route, the production time was reduced by about 50%. The quality of epoxide produced from either natural product was equivalent. Therefore (-)-shikimic acid is the preferred raw material. The absolute configuration of the epoxide was determined by X-ray single crystal structure analysis and it was demonstrated that the epoxide was stereo-isomerically pure.
- Federspiel, Muriel,Fischer, Rolf,Hennig, Michael,Mair, Hans-Jürgen,Oberhauser, Thomas,Rimmler, G?sta,Albiez, Thomas,Bruhin, Jürg,Estermann, Heinrich,Gandert, Carsten,G?ckel, Volker,G?tz?, Stephan,Hoffmann, Ursula,Huber, Gabriel,Janatsch, Günter,Lauper, Stephan,R?ckel-St?bler, Odette,Trussardi, Rene,Zwahlen, Andreas G.
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p. 266 - 274
(2013/09/08)
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- Polymer-bound p-alkoxybenzyl trichloracetimidates: Reagents for the protection of alcohols as benzyl ethers on solid-phase
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Wang and Tentagel resins ware converted into their trichloroacetimidate dervatives and used as polymer-bound benzylating reagents for a variety of alcohols. Loading and cleavage proceed in good to excellent yields in the presence of BF3.OEt2 and 1% TFA respectively. The resins have excellent shelf life.
- Hanessian, Stephen,Xie, Fang
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p. 733 - 736
(2007/10/03)
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- Alternative synthesis of (-)-malyngolide utilizing (-)-quinic acid
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(-)-Malyngolide, an antibiotic isolated from a blue-green algae, was synthesized starting from (-)-quinic acid.
- Matsuo, Keizo,Matsumoto, Takuya,Nishiwaki, Keiji
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p. 1213 - 1220
(2007/10/03)
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- Synthesis of Optically Active Isoquinuclidines Utilizing a Diastereoselectivity Control Element
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The development of a palladium-mediated cyclization via isomerization using a vinyl epoxide as an initiator and an amine as a terminator led to a facile cyclization to produce isoquinuclidines.The synthesis of the requisite cyclization precursor from (-)-
- Trost, Barry M.,Romero, Arthur G.
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p. 2332 - 2342
(2007/10/02)
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- REGIO- AND STEREOSELECTIVE SYNTHESIS OF THE CARBOCYCLIC ANALOGUE OF 3-DEOXY-β-D-MANNO-2-OCTULOPYRANOSONIC ACID (Β-KDO) (-)-QUINIC ACID.
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The carbocyclic analogue of β-KDO has been synthesized from (-)-quinic acid.
- Molin, H.,Pring, B. G.
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p. 677 - 680
(2007/10/02)
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- Studies related to Cyclopentanoid Natural Products. Part 1. Preparation of (4RS)- and (4R)-4-Hydroxy-2-hydroxymethylcyclopent-2-en-1-one; a Versatile Synthetic Intermediate
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The racemate of 2,5-dihydro-3-hydroxymethyl-2,5-dimethoxy-2-methylfuran (11), prepared from the reaction of 3-hydroxymethyl-2-methylfuran (12b), with bromine in methanol, is converted into the racemate of 4-hydroxy-2-hydroxymethylcyclopent-2-en-1-one (9a) when heated in aqueous dioxan buffered at pH 6.3. Methyl quinate (17b), obtained by treating D-(-)-quinic acid (17a) with methanolic hydrogen chloride, reacts with ammonia in methanol to give quinamide (17c) which affords 1,1'-ON-isopropylidenequinamide (27a) in the presence of acetone containing hydrogen chloride.Benzoyl chloride in pyridine transforms compound (27a) into the 5-O-benzoate (27b) which undergoes selective hydrolysis in hot aqueous acetic acid to give 5-O-benzoyl-1,1'-ON-isopropylidenequinamide (26).Sequential treatment of compound (26) with sodium periodate in aqueous tetrahydrofuran (THF) and pyrrolidinium acetate in hot benzene affords (5R,8R)-8-benzoyloxy-2,2-dimethyl-4-oxo-3-azaspironon-6-ene-6-carbaldehyde (32).The aldehyde (32) is transformed into (5R,8R)-8-hydroxy-6-hydroxymethyl-2,2-dimethyl-1-oxa-3-azaspironon-6-en-4-one (34a) by reaction with sodium borohydride in THF followed by methanolic sodium methoxide.Hydrazinolysis of the oxazolidinone ring of the last-described compound is effected in boiling hydrazine hydrate to yield (1R,4R)-1,4-dihydroxy-2-hydroxymethylcyclopent-2-ene-1-carbohydrazide (35a).Treatment of the acid hydrazide (35a) with nitrous acid and thermolysis of the derived acid azide (35b) gives (4R)-4-hydroxy-2-hydroxymethylcyclopent-2-en-1-one (9a).
- Elliott, John D.,Hetmanski, Michael,Stoodley, Richard J.,Palfreyman, Malcolm N.
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p. 1782 - 1789
(2007/10/02)
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