- Synthesis of Bungeanool, Isobungeanool, Dihydrobungeanool, Tetrahydrobungeanool, Hazaleamide, Lanyuamide III, and Analogues
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The bungeanools are a family of alkamide natural products isolated from the pericarps of Zanthoxylum bungeanum (Sichuan pepper), and they are structurally related to the sanshools. While the sanshools, especially hydroxy-?-sanshool, have been studied in a variety of contexts, research regarding the bungeanools has been much more limited. To facilitate their study, we have developed stereoselective syntheses of all four members of this family of compounds by using flexible routes that are also amenable to the synthesis of analogues. The key transformation in the syntheses was the stereoselective triphenylphosphine/ phenol-catalyzed isomerization of an alkynoate to the corresponding conjugated E,E-dienoate.
- Loo, Ying-Hui,Leakasindhu, Suleeporn,Kan, Chi-Ming,Toy, Patrick H.
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p. 1145 - 1156
(2021/11/09)
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- Antibacterial Activity of Hexadecynoic Acid Isomers toward Clinical Isolates of Multidrug-Resistant Staphylococcus aureus
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In the present study, the structural characteristics that impart antibacterial activity to C16 alkynoic fatty acids (aFA) were further investigated. The syntheses of hexadecynoic acids (HDA) containing triple bonds at C-3, C-6, C-8, C-9, C-10, and C-12 were carried out in four steps and with an overall yield of 34–78%. In addition, HDA analogs containing a sulfur atom at either C-4 or C-5 were also prepared in 69–77% overall yields, respectively. Results from this study revealed that the triple bond at C-2 is pivotal for the antibacterial activity displayed by 2-HDA, while the farther the position of the triple bond from the carbonyl group, the lower its bactericidal activity against gram-positive bacteria, including clinical isolates of methicillin-resistant Staphylococcus aureus (CIMRSA) strains. The potential of 2-HDA as an antibacterial agent was also assessed in five CIMRSA strains that were resistant to Ciprofloxacin (Cipro) demonstrating that 2-HDA was the most effective treatment in inhibiting their growth when compared with either Cipro alone or equimolar combinations of Cipro and 2-HDA. Moreover, it was proved that the inhibition of S. aureus DNA gyrase can be linked to the antibacterial activity displayed by 2-HDA. Finally, it was determined that the ability of HDA analogs to form micelles can be linked to their decreased activity against gram-positive bacteria, since critical micellar concentrations (CMC) between 50 and 300 μg/mL were obtained.
- Carballeira, Néstor M.,Chorna, Nataliya,Díaz, Damarith,Medina, Solymar,Mooney, Joseph,Morales-Guzmán, Christian,Ocasio-Malavé, Carlimar,Pereles-De-León, Tomás,Rivera-Román, Ashley,Sanabria-Ríos, David J.
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- Synthesis and Evaluation of a Series of Bis(pentylpyridinium) Compounds as Antifungal Agents
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A series of bis(4-pentylpyridinium) compounds with a variety of spacers between the pyridinium headgroups was synthesised, and the antifungal activity of these compounds was investigated. Lengthening the alkyl spacer between the pentylpyridinium headgroups from 12 to 16 methylene units resulted in increased antifungal activity against C. neoformans and C. albicans, but also resulted in increased hemolytic activity and cytotoxicity against mammalian cells. However, inclusion of an ortho-substituted benzene ring in the centre of the alkyl spacer resulted in decreased cytotoxicity and hemolytic activity, while maintaining antifungal potency. Replacement of the alkyl and aromatic-containing spacers by more hydrophilic ethylene glycol groups resulted in a loss of antifungal activity. Some of the compounds inhibited fungal PLB1 activity, but the low correlation of this inhibition with antifungal potency indicates PLB1 inhibition is unlikely to be the predominant mode of antifungal action of this class of compounds, with preliminary studies suggesting they may act via disruption of fungal mitochondrial function.
- Obando, Daniel,Koda, Yasuko,Pantarat, Namfon,Lev, Sophie,Zuo, Xiaoming,Bijosono Oei, Johanes,Widmer, Fred,Djordjevic, Julianne T.,Sorrell, Tania C.,Jolliffe, Katrina A.
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p. 1421 - 1436
(2018/07/29)
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- Method for preparing spring-cankerworm sex pheromones
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The invention relates to a method for preparing spring-cankerworm sex pheromones. The method includes the steps that alkynol serves as a raw material; hydroxyl is protected by dihydropyran ether; alkynyl and halogenated hydrocarbon are coupled; an acetylation reaction is carried out to generate a compound cis-4-tetradecenyl acetate and a compound cis-6-tetradecenyl acetate, wherein the total yield of the compound cis-4-tetradecenyl acetate and the total yield of the compound cis-6-tetradecenyl acetate are 58.1% and 55.2% respectively. The method has the advantages that the raw material is easy to obtain, the method is simple, the condition is mild, the total yield is high, cost is low, and the method is suitable for large-scale production. The method provides the necessary condition for replacing fruit-pest chemical-pesticide control with the wide application of the spring-cankerworm sex pheromones, and has the high theoretical significance and the quite good application value.
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-
Paragraph 0028; 0029; 0030
(2016/10/17)
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- STABILIZED POLYPEPTIDES AND USES THEREOF
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The present invention provides inventive stabilized STAT polypeptides, pharmaceutical compositions thereof, and methods of making and using inventive stabilized STAT polypeptides.
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- Dual amine and palladium catalysis in diastereo- and enantioselective allene carbocyclization reactions
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A pyrrolidine and Pd catalyzed diastereoselective carbocyclization of aldehyde and ketone-linked allenes has been developed. The cooperative organo/metal-catalyzed cyclization reaction, which presumably proceeds via an enamine intermediate, is efficient and broad in scope. Also, it has been extended to a catalytic asymmetric variant using diarylprolinol-based organocatalysts to afford substituted cyclopentane and pyrrolidine reaction products in up to 82% ee.
- Li, Meiling,Datta, Swarup,Barber, David M.,Dixon, Darren J.
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p. 6350 - 6353
(2013/02/23)
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- Polyunsaturated alkyl amides from echinacea: Synthesis of diynes, enynes, and dienes
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The synthesis of 20 alkyl amides, including 15 naturally occurring polyunsaturated alkyl amides previously identified from Echinacea spp. (1-13 and 62) or from Achilla sp. (55) and five previously unknown geometric isomers (23, 28, 67, 73, and 80), is described. Importantly, these amides include all of the major alkyl amides present in commercially used Echinacea extracts. The syntheses demonstrate methodology used for constructing alkyl amides containing conjugated diyne and isomerically pure enyne and diene moieties and may be adapted easily for the preparation of other alkyl amides present in Echinacea spp. Terminal-conjugated diynes were prepared by a Cadiot-Chodkiewitz coupling/deprotection sequence utilizing a protected bromoacetylene, and methyl-substituted diynes were made via a base-catalyzed rearrangement of terminal-skipped diynes. Conjugated dienes were prepared conveniently and with high stereoselectivity by the reduction of enynes or diynes with Rieke zinc. With the exception of 1-2 and 11-12, the alkyl amides are synthesized here for the first time, and their NMR data are consistent with that of the reported isolated natural compounds.
- Matovic, Nicholas J.,Hayes, Patricia Y.,Penman, Kerry,Lehmann, Reginald P.,De Voss, James J.
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p. 4467 - 4481
(2011/07/30)
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- The scope and limitations of intramolecular Nicholas and Pauson-Khand reactions for the synthesis of tricyclic oxygen-and nitrogen-containing heterocycles
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(Chemical Equation Presented) We studied the scope and limitations of a tandem intramolecular Nicholas/Pauson-Khand strategy for the synthesis of tricyclic oxygen- and nitrogen-containing heterocycles. This methodology enables conversion of simple acyclic starting materials into a series of previously unknown heterocyclic architectures. For the preparation of cyclic ethers (Z = O), tricyclic [5,6,5]- through [5,9,5]-systems (m = 1, n = 1-4) are available with the [5,7,5]- and [5,8,5]-systems amenable to quick and efficient synthesis. Tricyclic [5,7,5]- and [5,8,5]-amine-containing (Z = NTs) heterocycles can be successfully prepared. Attempts to make larger ring systems (Z = O, m = 2; Z = O, n = 5; or Z = NTs, n = 4-5) or prepare lactones via Nicholas reactions with carboxylic acid nucleophiles (available via oxidation of alcohol nucleophiles, Z = O) result in decomposition or dimerization. The latter process enables formation of 14-, 16-, and 18-membered ring diolides when using carboxylic acid nucleophiles. We also investigated the use of chiral amine promoters in the Pauson-Khand step but found no asymmetric induction.
- Closser, Kristina D.,Quintal, Miriam M.,Shea, Kevin M.
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scheme or table
p. 3680 - 3688
(2009/10/02)
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- NOVEL FATTY ACID ANALOGOUS
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The present invention relates to novel fatty acid analogous of the general formula (I): R1—[xi—CH2]n—COOR2 wherein R1 is: a C6-C24 alkene with one or more double bonds and/or with one or more triple bonds, and/or a C6-C24 alkyne, and/or a C6-C24 alkyl substituted in one or several positions with one or more compounds selected from the group comprising fluoride, chloride, hydroxy, C1-C4 alkoxy, C1-C4 alkylthio, C2-C5 acyloxy or C1-C4 alkyl, and wherein R2 represents hydrogen or C1-C4 alkyl, and wherein n is an integer from 1 to 12, and wherein i is an odd number and indicates the position relative to COOR2, and wherein Xi independent of each other are selected from the group comprising O, S, SO, SO2, Se and CH2, and with the proviso that at least one of the Xi is not CH2, and with the proviso that if R1 is an alkye, then the carbon-carbon triple bond is positioned between the (ω-1) carbon and the (ω-2) carbon, or between the (ω-2) carbon and the (ω-3) carbon, or between the (ω-3) carbon and the (ω-4) carbon, a salt, prodrug or complex thereof, which can be used for the treatment and/or prevention of syndrome X, obesity, hypertension, fatty liver, diabetes, hyperglycaemia, hyperinsulinemia and stenosis. Further, the invention relates to a nutritional composition comprising said fatty acid analogues, and a method for reducing the total weight, or the amount of adipose tissue in an animal.
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- Synthesis of medium- and large-sized lactones in an aqueous-organic biphasic system
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(Chemical Equation Presented) Saving solvent: An aqueous-ethyl acetate biphasic system allows an efficient synthesis of medium- and large-sized lactones by an intramolecular Tsuji-Trost reaction (see scheme, n = 1-5). The macrocyclization protocol does not require a large quantity of solvents or a slow-addition technique.
- Kinoshita, Hidenori,Shinokubo, Hiroshi,Oshima, Koichiro
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p. 2397 - 2400
(2007/10/03)
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- Total synthesis and assignment of the double-bond position and absolute configuration of (-)-pyrinodemin A
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(Matrix presented) The first asymmetric total synthesis of a structurally novel cis-cyclopent[c]isoxazolidine alkaloid, (-)-pyrinodemin A (3), which exhibits potent cytotoxicity, has been accomplished through a highly diastereoselective intramolecular nitrone - olefin cycloaddition reaction as the key step. Thus, it has been found that the hitherto unknown absolute configuration of pyrinodemin A is as indicated in the structural formula 3.
- Morimoto, Yoshiki,Kitao, Satoru,Okita, Tatsuya,Shoji, Takamasa
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p. 2611 - 2614
(2007/10/03)
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- Electrotelluration: A new approach to tri- and tetrasubstituted alkenes
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A novel electrotelluration process is described in which a Michael addition of an alkyl or aryl tellurolate anion occurs onto an activated alkyne with subsequent trapping of a vinyl anion with electrophiles (aldehydes and ketones) other than a proton. This process provides an efficient regio-and stereospecific route to tri- and tetrasubstituted alkenes. Methodologically significant examples of this chemistry were studied in which aryl and alkyl tellurolate anions were added to ω-keto alkynyl esters in a Michael reaction, and the incipient vinyl anions were trapped intramolecularly by the internal aldehydes. The reactive centers were tethered by different lengths of alkyl chains to form highly functionalized five-, six-, seven-, and eight-membered rings in modest to good yields.
- Marino, Joseph P.,Nguyen, Hanh Nho
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p. 6291 - 6296
(2007/10/03)
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- Study of the diastereoselectivity of cobalt-mediated [2+2+2] cycloadditions of substituted linear enediyne esters
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The preparation of substituted linear enediyne esters bearing the double bond either at the terminal or at internal position and the ester substituent either at the alkyne or at the alkene terminus is presented. Their cobalt(I)-mediated [2+2+2] cyclizations produce the η4-complexed tricyclic compounds in very good yields. The endo/exo selectivity depends on the position of the ester in the enediyne, but the cyclization can be totally diastereoselective. The asymmetric induction in the cyclization of enediynes bearing chiral esters has been studied; however, the diastereomeric excesses are low.
- Slowinski, Franck,Aubert, Corinne,Malacria, Max
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p. 3491 - 3500
(2007/10/03)
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- Enantioselective syntheses of monotetrahydrofuran annonaceous acetogenins tonkinecin and annonacin starting from carbohydrates
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The total synthesis of two mono-THF acetogenins, tonkinecin (1) and annonacin (2), is reported in full detail. Terminal acetylene 3 prepared from D-glucono-δ-lactone and asymmetric dihydroxylation was employed as a common intermediate for both targets 1 and 2. Pd(0)-catalyzed coupling reaction of 3 with vinyl iodides 4 and 5, the chiral centers of which were taken from D-xylose and S-(-)-ethyl lactate, afforded enyne 26 and 27, respectively. Selective hydrogenation of 26 or 27 with diimide followed by removal of MOM ethers completed the synthesis of 1. A coupling reaction between the lithium derivative of 3 and epoxide 6 in the presence of boron trifluoride etherate gave 42. Both chiral centers in epoxide 6 were taken from L-ascorbic acid. Subsequent catalytic hydrogenation and MOM protection led to 43b. Introduction of the butenolide moiety by aldol condensation of protected S-lactal followed by cleavage of all MOM ethers completed the synthesis of 2.
- Hu,Yu,Wu,Wu
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p. 853 - 861
(2007/10/03)
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- Formal synthesis of D-myo-inositol 1,4,5-tris(dihydrogen phosphate): Cyclization by an unusual ene reaction and use of the Bu2SnCl2/Bu2SnH2 reagent for generating an equatorial alcohol
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D-Glucose was converted into the propargyl silane aldehyde 5, which, on treatment with camphorsulfonic acid, cyclized with retention of silicon. The allenic product (7) was elaborated via ketone 24 into 4, which had previously been converted into D-myo-inositol 1,4,5-tris(dihydrogen phosphate). Selective reduction of the advanced intermediate 24 was accomplished with Bu2SnCl2/Bu2SnH2, a reagent mixture that shows a very strong preference for generating equatorial alcohols. The cyclization step leading to allene 7 was studied by examining a number of model compounds; the unusual retention of silicon appears to be limited to highly oxygenated substrates, such as 5 and its all-benzyl analogue (27).
- Clive, Derrick L. J.,He, Xiao,Postema, Maarten H. D.,Mashimbye, M. Jeffrey
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p. 4397 - 4410
(2007/10/03)
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- New and simple syntheses of the attractants of the female melon fly, dacus cucurbitee
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The attractant of the female melon fly, (E)-6-nonenyl acetate, and the two analogs, (E)-7-dodecenyl acetate and (E)-7-decenyl acetate were synthesized via hydrozirconation to control the regioselective coupling reactions and resulted in good yields.
- Yen, Yao-Pin,Chen, Pao-Hsing
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- The first synthesis of tonkinecin, an annonaceous acetogenin with a C-5 carbinol center
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(formula presented) Reported herein is the first synthetic approach to tonkinecin (1) which uses a palladium-catalyzed cross-coupling reaction between the tetrahydrofuran unit (4) and the butenolide (3) as the key step for constructing the backbone of 1. The stereogenic centers at C-5, C-21, C-22, and C-36 were derived from D-xylose, D-glucose, and L-lactate, respectively, whereas those at C-17, and C-18 were generated using Sharpless asymmetric dihydroxylation.
- Hu, Tai-Shan,Yu, Qian,Lin, Qi,Wu, Yu-Lin,Wu, Yikang
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p. 399 - 401
(2008/02/11)
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- Use of enyne compounds in the synthesis of insect pheromones
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A new approach has been developed to the synthesis of monogenic insect pheromones with acetogenin and macrolide structures, using the low reactivity of ozone and of 9-borabicyclo[3.3.1]nonane towards an acetylenic function as compared with a vinyl function.
- Ishmuratov,Ishmuratova,Odinokov,Tolstikov
-
-
- Studies related to fatty acids desaturation. II. Preparation of iso-linoleic and iso-vernolic acids
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New iso-vernolic and iso-linoleic acids have been prepared in order to study their potential inhibition action during in vivo desaturation of oleic acid in vegetal sources. - Keywords: Δ12-desaturase / modified fatty acids / Z,ω-octenyl bromides / iso-linoleic acids / iso-vernolic acids
- Gruiec, Regine,Noiret, Nicolas,Patin, Henri
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p. 699 - 705
(2007/10/02)
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- Pheromones: 87. An efficient synthesis of (6E,11Z)-6,11-hexadecadienyl acetate and (6E,11Z)-6,11-hexadecadienal: Female sex pheromone components of Antheraea pernyi and A. polyphemus (Lepidoptera: Saturniidae)
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(6E,11Z)-Hexadecadienyl acetate (15) and the corresponding aldehyde 16, the female sex pheromone components of Antheraea pernyi and A. polyphemus (Lepidoptera; Saturniidae) have been synthesized in 32% and 27% overall yields, respectively, and in 99% isomeric purity. Tetrahydropyran (1) was used as the starting material to obtain 5-bromopentanol (3) which was subsequently chain elongated to 7-(tetrahydropyran-2-yloxy)-1-heptyne (5) by the standard procedures. The organolithium compound from 5 was coupled with (Z)-1-bromo-4-nonene (11), obtained from the Wittig reaction between pentyltriphenylphosphonium bromide (9) and 4-(tetrahydropyran-2-yloxy)butanal (8) followed by bromination. The product, (Z)-1-(tetrahydropyran-2-yloxy)-11-hexadecen-6-yne (12) which resulted, was reduced with sodium/liquid ammonia to give 13 with the E-6 bond. Removal of the protecting group resulted in the desired alcohol 14 which on acetylation and oxidation gave the desired acetate 15 and the aldehyde 16, respectively.
- Bestmann,Gunawardena
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p. 1239 - 1241
(2007/10/02)
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- INSECT PHEROMONES AND THEIR ANALOGUES XL. SYNTHESIS OF DODEC-3Z-EN-11RS-OLIDE (FERRULACTONE II - A RACEMIC ANALOGUE OF A COMPONENT OF THE AGGREGATION PHEROMONE OF Cryptolestes ferrugineus
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A new route, based on the partial ozonolysis of ω-acetyl derivatives of alk-1-en-4-ynes, is proposed for the synthesis of 11RS-hydroxydodec-3Z-enoic acid, the cyclization of which gives dodec-3Z-en-11RS-olide (ferrulactone II) - a racemic analogue of one of the macrolide components of the aggregation pheromone of the rust-red grain beetle.
- Odinokov, V. N.,Ishmuratov, G. Yu.,Botsman, L. P.,Vakhidov, R. R.,Ladenkova, I. M.,et al.
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p. 369 - 374
(2007/10/02)
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- A New Methodology to Key Intermediates for Synthesizing Polyene Compounds
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ω-Alkoxy-(2E,4E)-dienoates, ω-oxo-(2E,4E)-dienoates and δ-oxo-α,β:γ,δ-dienones were prepared according to a new methodology shown in scheme I.High yield and high stereoselectivity were achieved by using transition metal catalyzed isomerization of ynoates or ynones instead of using Wittig-Horner-wadsworth-Emmons reaction to constitute the diene moiety.The usefulness of this methodology was demonstrated by the preparation of important synthetic precursors to polyene compounds and natural products such as 10--(2E,4E)-decadienoates, methyl 8--(2E,4E)-octadienoate, methyl 10-benzyloxy-(2E,4E)-decadienoate, 6-oxo-(2E,4E)-tetradecadienal, methyl 8-oxo-(2E,4E)-octadienoate, and retrofractamide A.
- Ma, Dawei,Lu, Xiyan
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p. 6319 - 6330
(2007/10/02)
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- SYNTHESE ET REACTIVITE DE SILANES PROPARGYLIQUES ω-FONCTIONNELS : PREPARATION DE VINYLIDENE-3 OXOLANNES, OXANNES, OXEPANNES ET OXOCANNES
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The ω-silyloxypropargyltrimethylsilanes regiospecifically react with aliphatic and aromatic aldehydes to lead to vinylidene oxigen-containing heterocycles, such as 3-vinylidene oxolanes, oxanes, oxepanes and oxocanes.
- Pornet, J.,Damour, D.,Miginiac, L.
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p. 2017 - 2024
(2007/10/02)
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- Systematic Syntheses and Charactarization of Dodecadien-1-ols with Conjugated Double Bond, Lepidopterous Sex Pheromones
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Four geometrical isomers of 5,7-, 6,8-, 7,9- and 8,10-dodecadein-1-ols were systematically synthesized by two routes.One involved the Wittig reaction between (E)-2-alkenal and a phosphorane with an appropriate carbon chain, and yielded a mixture of (E,Z)- and (E,E)-isomers in a ratio of ca. 3:2.The other route comprised of the Wittig reaction of a 2-alkynal and the stereoselective reduction of the triple bond to a (Z)-double bond via hydroboration with dicyclohexylborane to give a mixture of (Z,Z)- and (Z,E)-isomers in a ratio of 6:1 10:1.Both the mixtures were separately chromatographed on a silica gel column impregnated with silver nitrate to give four geometrically pure isomers.With 9,11-diene they were analysed by GC on a capillary column, HPLC, silver nitrate impregnated TLC, and 13C NMR.
- Ando, Tetsu,Kurotsu, Yuichi,Kaiva, Mieko,Uchiyama, Masaaki
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p. 141 - 148
(2007/10/02)
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- Oxidized Leukotrienes: Synthesis of 20-OH and 20-COOH LTD4. Possible Metabolites in the Lipoxygenase Pathway
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Leukotriene LTD4 analogs 20-OH LTD4 16 and 20-COOH LTD4 17 were synthesized.These ω-oxidative derivatives are possible metabolites of the natural product.
- Adams, Julian,Milette, Suzanne,Rokach, Joshua,Zamboni, Robert
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p. 2179 - 2182
(2007/10/02)
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- VINYL CATIONS. 40. pi - AND sigma -ROUTES TO VINYL CATIONS. SOLVOLYSES OF 2-METHYLCYCLOHEXENYL, CYCLOPENTYLIDENEETHYL, HEX-5-YN-1-YL, AND RELATED TRIFLATES.
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Three triflates were solvolyzed at various temperatures in water-alcohol mixtures, in TFE-water mixtures, in TFA, in TFIP, in HFIP, and in 100% TFE in the presence of various buffers and the resulting products were determined. The three reactants were also solvolyzed in a standard mixture (1:100:100 equals triflate:TFE:Na//2CO//3) at various temperatures, and the yields of products were compared. The solvolysis products were shown to be under kinetic control.
- Hanack,Fuchs,Collins
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p. 4008 - 4017
(2007/10/12)
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