The application of (Z)-3-aryl-3-haloenoic acids to the synthesis of (Z)-5-benzylidene-4-arylpyrrol-2(5H)-ones

Studies directed at the synthesis of (Z)-5-benzylidene-4-arylpyrrol-2(5H)-ones from (Z)-3-aryl-3-haloenoic acids are described. The successful strategy relies on the preparation of (Z)-3-aryl-3-haloenoic acids from acetophenones through the corresponding (Z)-3-aryl-3-haloenals and the conversion of the (Z)-3-aryl-3-haloenoic acids to (Z)-5-benzylidene-4-aryl-5H-furan-2-ones. The furanones were subsequently treated with primary amines and dehydrated to the corresponding (Z)-5-benzylidene-4-arylpyrrol-2(5H)-ones.     

A short catalytic enantioselective synthesis of the proinflammatory eicosanoid 12(R)-hydroxy- 5(Z),8(Z),10(E),14(Z)-eicosatetraenoic acid (12(R)-HETE)

A new and effective pathway is described for the synthesis of 12(R)-HETE and the 12(S)-enantiomer from the common intermediates 4 and 8.     

Synthesis of new ionic liquids based on (5Z,9Z)-alkadienoic acids and choline

Efficient synthesis of ionic liquids based on stereoisomerically pure natural and synthetic higher (5Z,9Z)-alkadienoic acids and choline hydroxide was developed. The key unsaturated carboxylic acids were prepared using the stereoselective cross-cyclomagnesiation reaction of aliphatic and oxygen-containing 1,2-dienes with EtMgBr in the presence of Mg metal and Cp₂TiCl₂ catalyst.     

Conformations of the Ten-membered Ring in 5, 10-Secosteroids. III: (Z)-3β- and (Z)-3α-Hydroxy-5, 10-seco-1 (10)-cholesten-5-one Esters and (Z)-5, 10-seco-1 (10)-Cholestene-3, 5-dione

(Z)-3β-Acetoxy- and (Z)-3 α-acetoxy-5, 10-seco-1 (10)-cholesten-5-one ( 6a ) and ( 7a ) were synthesized by fragmentation of 3β-acetoxy-5α-cholestan-5-ol ( 1 ) and 3α-acetoxy-5β-cholestan-5-ol ( 2 ), respectively, using in both cases the hypoiodite reaction (the lead tetraacetate/iodine version). The 3β-acetate 6a was further transformed, via the 3β-alcohol 6d to the corresponding (Z)-3β-p-bromobenzoate ester 6b and to (Z)-5, 10-seco-1 (10)-cholestene-3, 5-dione ( 8 ) (also obtainable from the 3α-acetate 7a ). The ¹H-and ¹³C-NMR. spectra showed that the (Z)-unsaturated 10-membered ring in all three compounds ( 6a , 7a and 8 ) exists in toluene, in only one conformation of type C ₁, the same as that of the (Z)-3β-p-bromobenzoate 6b in the solid state found by X-ray analysis. The unfavourable relative spatial factors (interdistance and mutual orientation) of the active centres in conformations of type C ₁ are responsible for the absence of intramolecular cyclizations in the (Z)-ketoesters 6 and 7 ( a and c ).     

松毛虫性信息素(5Z,7E)-十二碳二烯醇的立体选择性合成

从简单原料乙炔出发,通过炔对丙烯醛的加成反应得到7-溴代-(4Z,6E)-庚二烯醛,再经乙二醇保护、Pd催化偶联、水解、Wittig反应和还原等步骤,立体选择性地得到松毛虫性信息素(5Z,7E)-十二碳二烯醇,其结构通过IR,NMR和MS等技术得到确认.     

New synthesis of (Z)-5- and (Z)-7-monoene components of insect sex pheromones of the Lepidoptera order

A new procedure was developed for the synthesis of (Z)-5- and (Z)-7-monoene components of sex pheromones of Lepidoptera insects based on cometathesis of readily accessible cycloocta-1,5-diene and ethylene. Published inIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 7, pp. 1304–1307, July, 2000.     

Synthesis of Z and E-(2',5'-dimethoxyphenyl)-methylene-butyrolactones

Pseudotaxlactone was isolated by Zhang1 from Taxaceae plant pseudotaxus chienii(Cheng) Cheng. It's structure was tentatively assigned as 5-(4-hydroxy-3,5- 20%(Z,9), 4%(E,8).The intermediate 7 was synthesized using 2,5-dimethoxy-phenyl acetic acid as astarting material. However, cyclization reaction gave Z-(2,5-dimethoxy-phenyl)methylene-butyrolactone 9 (20%) and E-(2,5-dimethoxy-phenyl)-methylelactone 8 (4%), instead of the desired counterpart with endocyclic unsaturation. Thereaction of t…     

Synthesis and characterization of (Z)-5-arylmethylidene-rhodanines with photosynthesis-inhibiting properties

A series of rhodanine derivatives was prepared. The synthetic approach, analytical and spectroscopic data of all synthesized compounds are presented. Lipophilicity of all the discussed rhodanine derivatives was analyzed using the RP-HPLC method. The compounds were tested for their ability to inhibit photosynthetic electron transport (PET) in spinach (Spinacia oleracea L.) chloroplasts and reduce chlorophyll content in freshwater alga Chlorella vulgaris. Structure-activity relationships between the chemical structure, physical properties and biological activities of the evaluated compounds are discussed. For majority of the tested compounds the lipophilicity of the compound and not electronic properties of the R1 substituent were decisive for PET-inhibiting activity. The most potent PET inhibitor was (5Z)-5-(4-bromobenzylidene)-2-thioxo-1,3-thiazolidin-4-one (IC(50) = 3.0 μmol/L) and the highest antialgal activity was exhibited by (5Z)-5-(4-chlorobenzylidene)-2-thioxo-1,3-thiazolidin-4-one (IC(50) = 1.3 μmol/L).     

Biosynthesis of δ-Jasmin Lactone ( = (Z)-Dec-7-eno-5-lactone) and (Z,Z)-Dodeca-6,9-dieno-4-lactone in the Yeast Sporobolomyces odorus

(all-Z)-(9,10,12,13,15,16-²H₆)Octadeca-9,12,15-trienoic acid ( = α-linolenic acid; D₆- 4 ) was synthesized to investigate the biochemical formation of linolenic-acid-derived aroma compounds in cultures of the yeast Sporobolomyces odorus, using an established gas chromatographic/mass spectrometric (GC/MS) method. Three compounds were identified as labeled: (Z)-dec-7-eno-5-lactone (δ-jasmin lactone), (Z,Z)-dodeca-6,9-dieno-4-lactone, and (2E,4Z)-hepta-2,4-dienoic acid. Both lactones were biosynthesized mostly under conservation of the initial configuration from their corresponding oxygenated linolenic-acid intermediates. The application of (13S,9Z,11E,15Z)-13-hydroxy(9,10,12,13,15, 16-²H₆)octadeca-9,11,15-trienoic acid (D₆- 7 ) as a OH-functionalized precursor of δ-jasmin lactone allowed to gain insight into the stereochemical course of the biosynthesis to both enantiomers of this lactone. In this experiment, 88.3% of the metabolized labeled precursor was transformed under retention of the original configuration of the (R)-enantiomer. This investigation is also a contribution to a better understanding of the C?C bond isomerization steps which took place during the β-oxidative degradation of the substrate.     

(2Z)-3-(5-Hydroxy-4-oxo-4H-chromen-3-yl)acrylonitrile

The title compound, C₁₂H₇NO₃, consists of a chromone moiety substituted in position 3 with an acrylonitrile group in a Z configuration. The two planar groups are twisted with respect to one another. The only significant hydrogen bond in the structure is an intra­molecular O—H·O bond. π–π contacts connecting aromatic groups and C—H·O inter­molecular weak inter­actions lead to a supramolecular layer arrangement.     

Das Carotinoidspektrum der Hagebutten von Rosa pomifera: Nachweis von (5Z)-Neurosporin; Synthese von (3R, 15Z)-Rubixanthin

Carotenoids from Hips of Rosa pomifera: Discovery of (5Z)-Neurosporene; Synthesis of (3R, 15Z)-Rubixanthin Extensive chromatographic separations of the mixture of carotenoids from ripe hips of R. pomifera have led to the identification of 43 individual compounds, namely (Scheme 2): (15 Z)-phytoene (1) , (15 Z)-phytofluene (2) , all-(E)-phytofluene (2a) , ξ-carotene (3) , two mono-(Z)-ξ-carotenes ( 3a and 3b ), (6 R)-?, ψ-carotene (4) , a mono-(Z)-?, ψ-carotene (4a) , β, ψ-carotene (5) , a mono-(Z)-β, ψ-carotene (5a) , neurosporene (6) , (5 Z)-neurosporene (6a) , a mono-(Z)-neurosporene (6b) , lycopene (7) , five (Z)-lycopenes (7a–7e) , β, β-carotene (8) , two mono-(Z)-β, β-carotenes (probably (9 Z)-β, β-carotene (8a) and (13 Z)-β, β-carotene (8b) ), β-cryptoxanthin (9) , three (Z)-β-cryptoxanthins (9a–9c) , rubixanthin (10) , (5′ Z)-rubixanthin (=gazaniaxanthin; 10a ), (9′ Z)-rubixanthin (10b) , (13′ Z)- and (13 Z)-rubixanthin (10c and 10d , resp.), (5′ Z, 13′ Z)- or (5′ Z, 13 Z)-rubixanthin (10e) , lutein (11) , zeaxanthin (12) , (13 Z)-zeaxanthin (12b) , a mono-(Z)-zeaxanthin (probably (9 Z)-zeaxanthin (12a) ), (8 R)-mutatoxanthin (13) , (8 S)-mutatoxanthin (14) , neoxanthin (15) , (8′ R)-neochrome (16) , (8′ S)-neochrome (17) , a tetrahydroxycarotenoid (18?) , a tetrahydroxy-epoxy-carotenoid (19?) , and a trihydroxycarotenoid of unknown structure. Rubixanthin (10) and (5′ Z)-rubixanthin (10a) can easily be distinguished by HPLC. separation and CD. spectra at low temperature. The synthesis of (3 R, 15 Z)-rubixanthin (29) is described. The isolation of (5 Z)-neurosporene (6a) supports the hypothesis that the ?-end group arises by enzymatic cyclization of precursors having a (5 Z)- or (5′ Z)-configuration.     

(E)-, (Z)-Interconversion in 3-aroylmethyl-5-arylmethylene-2,4-dioxo-1,3-thiazolidines

Summary The (E)-, (Z)-interconversion in 3-aroylmethyl-5-arylmethylene-2,4-dioxo-1,3-thiazolidines is simply achieved upon treating with phenylhydrazine in acetic acid solutions. Configurational assignments are based on¹H-NMR spectral data.

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(E)-, (Z)-Interkonversion von 3-Aroylmethyl-5-arylmethylen-2,4-dioxo-1,3-thiazolidinen

Zusammenfassung Die (E)-, (Z)-Interkonversion in 3-Aroylmethyl-5-arylmethylen-2,4-dioxo-1,3-thiazolidinen wird durch Behandlung mit Phenylhydrazin in essigsaurer Lösung erreicht. Die Zuordnung von Konfigurationen basiert auf¹H-NMR-Daten.

     

Two (E,E)- and (Z,E)-thiazol-5-ylpenta-2,4-dienones

In order to characterize the structural elements that might play a role in non-covalent DNA binding by the antitumor antibiotic leinamycin, we have solved the crystal structures of the two leinamycin analogs, methyl (R)-5-{2-[1-(tert-butoxy­carbonyl­amino)­ethyl]­thia­zol-4-yl}penta-(E,E)-2,4-dienoate, C₁₆H₂₂N₂O₄S, (II), and 2-methyl-8-oxa-16-thia-3,17-di­aza­bicyclo­[12.2.1]­heptadeca-(Z,E)-1(17),10,12,14-tetraene-4,9-di­one, C₁₄H₁₆N₂O₃S, (III). The penta-2,4-dienone moiety in both of these analogs adopts a conformation close to planarity, with the thia­zole ring twisted out of the plane by 12.9 (2)° in (II) and by 21.4 (4)° in (III).