- Syntheses of all eight stereoisomers of conidendrin
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All eight stereoisomers of conidendrin were synthesized from (1 R,2 S,3 S)-1-(4-benzyloxy-3-methoxyphenyl)-3-(4-benzyloxy-3-methoxybenzyl)-2- hydroxymethyl-1,4-butanediol ((+)-4) and its enantiomer with high optical purity. The configurations at 4-positio
- Nishiwaki, Hisashi,Shirakata, Hinako,Yamauchi, Satoshi
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- TRIP-Catalyzed Asymmetric Synthesis of (+)-Yatein, (-)-α-Conidendrin, (+)-Isostegane, and (+)-Neoisostegane
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The asymmetric allylation under the assistance of catalytic amounts of 3,3′-bis(2,4,6-triisopropylphenyl)-1,1′-binaphthyl-2,2′-diyl hydrogen phosphate (TRIP) allows the concise construction of the lignan scaffold from simple aldehydes and allylic bromides with full control of the two formed stereocenters. This young methodology has been employed to synthesize four naturally and pharmaceutically active lignans. Members of the dibenzylbutyrolactone, the tetraline, and the dibenzocyclooctadiene classes have been synthesized in 40-47% overall yield along four-step synthetic routes.
- Hartmann, Peter,Lazzarotto, Mattia,Steiner, Lorenz,Cigan, Emmanuel,Poschenrieder, Silvan,Sagmeister, Peter,Fuchs, Michael
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p. 5831 - 5837
(2019/04/25)
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- Derivatives of the Lignan 7′-Hydroxymatairesinol with Antioxidant Properties and Enhanced Lipophilicity
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The lignan 7′-hydroxymatairesinol (1), extracted from the knotwoods of fir (Abies alba), spruce (Picea abies), and Douglas fir (Pseudotsuga menziesii), exhibited unexpected reactivity when esterification reactions were attempted on the hydroxy group at position C-7′. To circumvent the rapid intramolecular cyclization procedure, leading quantitatively to the lignan conidendrin (7), a simple strategy for 7′-esterification of 1 under mild conditions (three steps, up to 80% overall yield) was developed. Compared to hydroxymatairesinol (1) (log K′w = 1.49), the derivatives (2-5) had increased lipophilicity with log K′w > 3.1, as determined by a UHPLC method. Compounds 1-5 exhibited potent antioxidant properties in the same range as the standards ascorbic acid and α-tocopherol (IC50 = 20-25 μM) and higher than that of BHT using a DPPH radical-scavenging assay.
- Moraux, Thomas,Dumar?ay, Stéphane,Gérardin, Philippe,Gérardin-Charbonnier, Christine
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supporting information
p. 1783 - 1790
(2017/06/28)
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- Gold particle size effect in biomass-derived lignan hydroxymatairesinol oxidation over Au/Al2O3 catalysts
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The heterogeneously catalyzed aerobic selective oxidation of naturally occurring lignan hydroxymatairesinol (HMR) to another lignan oxomatairesinol (oxoMAT) was carried out at 70°C and atmospheric pressure over gold nanoparticles with different sizes supp
- López, Martín,Simakova, Olga A.,Murzina, Elena V.,Willf?r, Stefan M.,Prosvirin, Igor,Simakov, Andrey,Murzin, Dmitry Yu.
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p. 248 - 255
(2015/02/19)
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- Synthesis and structural analysis of sterically hindered chiral 1,4-diol ligands derived from the lignan hydroxymatairesinol
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The readily available natural lignan hydroxymatairesinol was transformed into sterically hindered and optically pure diphenyl, di-2-naphthyl, and tetramethyl 1,4-diol derivatives via arylation/alkylation of the aryltetralinbutyrolactone lignan (-)-conidendrin. In addition, the diastereoselective formation of stable hemiketals from the highly substituted butyrolactone was studied in detail. The conformations of the molecules prepared were studied computationally at molecular mechanics (MM), Hartree-Fock (HF)/6-31G*, and (DFT/B3LYP/TZVP) levels including entropy contributions and by NMR-spectroscopy. The conformations adopted showed that these novel chiral 1,4-diols may be suitable as chiral ligands for the development of new chiral transition metal and organo catalysts.
- Brusentsev, Yury,Sandberg, Thomas,Hotokka, Matti,Sj?holm, Rainer,Eklund, Patrik
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supporting information
p. 1112 - 1115
(2013/04/10)
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- Oxidative dehydrogenation of a biomass derived lignan - Hydroxymatairesinol over heterogeneous gold catalysts
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Synthesis of the lignan oxomatairesinol via oxidative dehydrogenation of the naturally occurring lignan hydroxymatairesinol was studied over gold catalysts supported on C, TiO2, SiO2, Al2O 3, and MgO. In order to investigate the reaction performance over the gold catalyst, synthesis of lignan oxomatairesinol was carried out in different organic solvents/water mixtures under synthetic air and nitrogen atmosphere at 373 K, and using also isolated hydroxymatairesinol isomers as a starting material. The results were compared with those obtained over palladium catalysts. Synthesized supported gold catalysts as well as the corresponding supports were characterized by TEM, XRD, ICP-OES, CO2-TPD, FTIR (using pyridine as a probe molecule), and XPS. Gold catalysts were shown to display superior performance compared with palladium ones: the activity was 4 times higher, with selectivity toward oxomatairesinol being 100%, while 60-85% were obtained over palladium catalysts. In contrast to palladium, the activity of gold catalysts is high in aerobic conditions and water-propan-2-ol mixture. However, activity and selectivity of gold catalysts were shown to be dependent on the electronic state of the metal and, similar to palladium catalysts, on the support acidity.
- Simakova, Olga A.,Murzina, Elena V.,Maeki-Arvela, Paeivi,Leino, Anne-Riikka,Campo, Betiana C.,Kordas, Krisztian,Willfoer, Stefan M.,Salmi, Tapio,Murzin, Dmitry Yu.
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experimental part
p. 54 - 64
(2011/09/20)
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- Radical carboxyarylation approach to lignans. Total synthesis of (-)-arctigenin, (-)-matairesinol, and related natural products
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Total syntheses of seven biologically important lignan natural products, including (-)-arctigenin, (-)-matairesinol, and (-)α-conidendrin, by way of a highly stereoselective domino radical sequence is presented. The reported stereochemistry of the natural product 7-hydroxyarctigenin is shown to be erroneous; a diastereoisomeric structure is assigned to the natural product.
- Fischer, Joshua,Reynolds, Aaron J.,Sharp, Lisa A.,Sherburn, Michael S.
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p. 1345 - 1348
(2007/10/03)
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- Intermolecular C-H activation at benzylic positions: Synthesis of (+)-imperanene and (-)-α-conidendrin
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An efficient C-H activation of primary benzylic positions by means of rhodium carbenoid induced C-H insertions is described. This key step was used in concise syntheses of (+)-imperanene and (-)-α-conidendrin.
- Davies, Huw M. L.,Jin, Qihui
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p. 941 - 949
(2007/10/03)
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(-)-α-Conidendrin 1 was synthesized according to a general reactionscheme that could be applied to other retrolignans as well. Thus, treatment of the optically active β-benzyl-γ-butyrolactone (R)-(+)-4 with NBS, followed with benzyl alcohol, selectively introduced a benzyloxy group in the benzylic position and afforded the mixture of epimers 7. α-Alkylation of the lithium enolate of the corresponding silyl ethers 10, with O-benzylvanillyl bromide 11, gave the trans disubstituted lactones 13 (2 epimers). Catalytic hydrogenolysis (Pd-C) of 13 selectively split the aryl benzyl ether linkage, and gave the compounds 14. Intramolecular Friedel-Crafts cyclization of the latter, using the benzyloxy group as the leaving group, was induced with BF3-Et2O and afforded (-)-α-conidendrin 1 in 36% overall yield from methyl α-vanillylhemis uccinate (R)-(+)-17.
- Boissin, Partrick,Dhal, Robert,Brown, Eric
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p. 687 - 694
(2007/10/02)
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- ETUDES DE LIGNANES 7 - SYNTHESES TOTALES DES (+-)-α ET -β-CONIDENDRINES ET DES METHYL (+-)-α ET -β-CONIDENDRALS
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Michael addition of the carbanion of the dithian 8 on butenolide, followed by alkylation with the benzylic bromide 11 and regeneration of the ketonic carbonyl group, gave the α,β-disubstituted lactone 13.Reduction of the ketonic carbonyl of the latter usi
- Dhal, Robert,Nabi, Yahia,Brown, Eric
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p. 2005 - 2016
(2007/10/02)
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- Chemistry of the Podocarpaceae. LXIX. Further Lignans from the Wood of Dacrydium intermedium
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Structures and absolute configurations are established for five new lignans isolated from the wood of the New Zealand podocarp Dacrydium intermedium Kirk.X-ray crystallography has been used to confirm the structure of one of the new lignans.Structures for two further inseparable lignans are provisionally assigned.The structure of one of three lignans previously isolated from the wood is revised.
- Cambie, Richard C.,Clark, George R.,Craw, Peter A.,Jones, Tony C.,Rutledge, Peter S.,Woodgate, Paul D.
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p. 1631 - 1645
(2007/10/02)
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- SYNTHESE TOTALE DE LA (d,l) α-CONIDENDRINE
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Michael addition of the carbanion of the dithian 7 (derived from O-benzylvanillin) on butenolide, afforded the saturated lactone 8.Alkylation of the latter with the benzylic bromide 6, followed by regeneration of the carbonyl group gave the α,β-disubstituted lactone 10.Reduction of the ketonic carbonyl group of compound 10 using NaBH4, followed by treatment with CF3CO2H and catalytic hydrogenolysis afforded (d,l)α-conidendrin 1.
- Nabi, Yahia,Dhal, Robert,Brown, Eric
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p. 1543 - 1546
(2007/10/02)
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