Bibliografías temáticas / Absolute asymmetric catalysis

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Literatura académica sobre el tema "Absolute asymmetric catalysis"

Autor: Grafiati

Publicado: 25 de mayo de 2024

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Artículos de revistas sobre el tema "Absolute asymmetric catalysis"

Kaupp, Gerd y Michael Haak. "Absolute Asymmetric Synthesis by Irradiation of Chiral Crystals". Angewandte Chemie International Edition in English 32, n.º 5 (mayo de 1993): 694–95. http://dx.doi.org/10.1002/anie.199306941.

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Lin, Yun-Ming, Zhongtao Li y Julie Boucau. "Predicting the R/S absolute configuration in asymmetric bifunctional catalysis (ABC)". Tetrahedron Letters 48, n.º 30 (julio de 2007): 5275–78. http://dx.doi.org/10.1016/j.tetlet.2007.05.131.

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Buchcic-Szychowska, Aleksandra, Anna Zawisza, Stanisław Leśniak y Michał Rachwalski. "Highly Efficient Asymmetric Morita–Baylis–Hillman Reaction Promoted by Chiral Aziridine-Phosphines". Catalysts 12, n.º 4 (31 de marzo de 2022): 394. http://dx.doi.org/10.3390/catal12040394.

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Continuing our research on the use of organophosphorus derivatives of aziridines in asymmetric synthesis and expanding the scope of their applicability, chiral aziridine-phosphines obtained earlier in our laboratory were used as chiral catalysts in the asymmetric Morita–Baylis–Hillman reaction of methyl vinyl ketone and methyl acrylate with various aromatic aldehydes. The desired chiral products were formed in moderate to high chemical yields and with enantiomeric excess reaching value of 98% ee in some cases. The use of catalysts being pairs of enantiomers led to the desired products with opposite absolute configurations.

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Feringa, Ben L. y Richard A. van Delden. "Absolute Asymmetric Synthesis: The Origin, Control, and Amplification of Chirality". Angewandte Chemie International Edition 38, n.º 23 (7 de diciembre de 1999): 3418–38. http://dx.doi.org/10.1002/(sici)1521-3773(19991203)38:23<3418::aid-anie3418>3.0.co;2-v.

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Barron, L. D. "True and false chirality and absolute asymmetric synthesis". Journal of the American Chemical Society 108, n.º 18 (septiembre de 1986): 5539–42. http://dx.doi.org/10.1021/ja00278a029.

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Yamamoto, Satoshi, Kenji Matsuda y Masahiro Irie. "Absolute Asymmetric Photocyclization of a Photochromic Diarylethene Derivative in Single Crystals". Angewandte Chemie International Edition 42, n.º 14 (11 de abril de 2003): 1636–39. http://dx.doi.org/10.1002/anie.200250417.

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Kuhn, Alexander y Peer Fischer. "Absolute Asymmetric Reduction Based on the Relative Orientation of Achiral Reactants". Angewandte Chemie International Edition 48, n.º 37 (1 de septiembre de 2009): 6857–60. http://dx.doi.org/10.1002/anie.200902841.

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Wu, Yusheng, Lothar Esser y Jef K. De Brabander. "Revision of the Absolute Configuration of Salicylihalamide A through Asymmetric Total Synthesis". Angewandte Chemie 39, n.º 23 (1 de diciembre de 2000): 4308–10. http://dx.doi.org/10.1002/1521-3773(20001201)39:23<4308::aid-anie4308>3.0.co;2-4.

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Bielski, Roman y Michal Tencer. "Macroscopically chiral system of three independent orientational effects as a condition for absolute asymmetric synthesis". Canadian Journal of Chemistry 81, n.º 9 (1 de septiembre de 2003): 1029–37. http://dx.doi.org/10.1139/v03-128.

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The paper introduces the concept of using three independent, macroscopic factors affecting mutual orientation of the reactant molecules to accomplish absolute asymmetric synthesis. Unlike with other methodologies of asymmetric synthesis in physical fields, none of the utilized factors is chiral in itself (as, e.g., circularly polarized light would be), but the combination of the three constitutes a macroscopically chiral influence. Examples of applicable directional factors are time-even vector fields (e.g., electric field and the directional effects of surfaces and interfaces) and the time-odd directional transport with encounter control. The directional factors employed may act simultaneously or, if their effect can be preserved, consecutively, thus allowing, e.g., a repeat use of the electric field. The electric field strength needed to achieve a practically useful degree of molecular orientation was estimated to be ca. 3 MV/cm, which is now commonly achieved with organic materials in the area of nonlinear optics. Practical implications are discussed, as well as the implications for the origins of natural homochirality.Key words: macroscopic chirality, absolute asymmetric synthesis, homochirality, physical fields.

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Kaimori, Yoshiyasu, Yui Hiyoshi, Tsuneomi Kawasaki, Arimasa Matsumoto y Kenso Soai. "Formation of enantioenriched alkanol with stochastic distribution of enantiomers in the absolute asymmetric synthesis under heterogeneous solid–vapor phase conditions". Chemical Communications 55, n.º 36 (2019): 5223–26. http://dx.doi.org/10.1039/c9cc01875a.

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Tesis sobre el tema "Absolute asymmetric catalysis"

Sallembien, Quentin. "Controlling handedness of triarylamine trisamide assemblies by means of circularly polarized light or chiral additives". Electronic Thesis or Diss., Sorbonne université, 2021. http://www.theses.fr/2021SORUS499.

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Pour ouvrir la voie à la catalyse asymétrique absolue, des polymères supramoléculaires de triarylamine trisamide (TATA) ont été étudiés sous l'influence de la lumière polarisée circulairement (LPC) et d’additifs/solvants chiraux. Les propriétés associatives de TATA aux chaînes latérales saturées ou diacétyléniques furent sondées en présence ou non de LPC par SANS, UV–Vis–NIR, FT–IR, RMN et RPE. Les deux types d’autoassemblage formés par ces molécules, agrégats non-spécifiques et assemblages hélicoïdaux par liaisons hydrogène, sont en compétition et la nature de l’espèce majoritaire dépend des conditions. La lumière et les espèces radicalaires cationiques qui en découlent n’induisent pas de changement significatif dans leur structure, bien que le co-assemblage entre espèces neutres et radicalaires soit démontré. Dans ces co-assemblages, les électrons non-appariés sont soit lentement délocalisés en solution, soit rapidement délocalisés au sein de fibres alignées dans des films minces. Notre étude par dichroïsme circulaire écarte la possibilité d'utiliser la LPC pour orienter la chiralité des assemblages de TATA dans les conditions décrites dans la littérature. Enfin, des monomères TATA comportant une unité triphénylphosphine furent synthétisés. Leur étude dans le toluène, dichlorométhane et décaline a montré la formation d’assemblages par liaisons hydrogène thermoréversible. Une série d’additifs et de solvants énantiopurs fut employée sans succès afin d’en contrôler la chiralité supramoléculaire. La caractérisation fine des assemblages réalisée dans cette thèse ouvre la voie à un meilleur contrôle de la structure des assemblages hélicoïdaux fonctionnalisés
To pave the way for the absolute asymmetric catalysis, triarylamine trisamide (TATA) supramolecular helical polymers were investigated under the influence of circularly polarized light (CPL) and chiral additives/solvents. The association properties of TATA molecules with saturated or diacetylenic side chains were probed in presence and absence of CPL, by SANS, UV–Vis–NIR, FT–IR, NMR and EPR. The two types of self-assembly formed by these TATA molecules, non-specific aggregates and hydrogen-bonded helical stacks, are in competition and the majority assembly depends on conditions (concentration, temperature, solution/gel/solid). Light and the resulting radical cationic species do not strongly affect the structure of these assemblies, while the co-assembly between neutral and radical cationic species is demonstrated. In these co-assemblies, the unpaired electrons are either slowly delocalized in solution, because of the disorder in assemblies, or rapidly delocalized within long aligned fibers of thin films. Our CD study discards the possibility of using CPL to direct the handedness of TATA-SDA assemblies in the conditions stated in the literature. Finally, the synthesis of TATA ligands bearing a triphenylphosphine unit was achieved. Their study in toluene, dichloromethane and decalin showed the thermoreversible formation of long hydrogen-bonded stacks. Despite the use of a library of enantiopure small molecules as chiral additives or solvents, no biased supramolecular helices were detected. The in-depth characterization of assemblies carried out in this thesis paves the way towards a better control of the structure of functionalized helical assemblies

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Gruner, Konstanze K., Thomas Hopfmann, Kazuhiro Matsumoto, Anne Jäger, Tsutomu Katsuki y Hans-Joachim Knölker. "Efficient iron-mediated approach to pyrano[3,2-a]carbazole alkaloids - first total syntheses of O-methylmurrayamine A and 7-methoxymurrayacine, first asymmetric synthesis and assignment of the absolute configuration of (−)-trans-dihydroxygirinimbine". Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2014. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-138748.

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Iron-mediated oxidative cyclisation provides an efficient approach to pyrano[3,2-a]carbazole alkaloids. Thus, improved routes to girinimbine and murrayacine as well as the first total syntheses of O-methylmurrayamine A and 7-methoxymurrayacine are reported. Asymmetric epoxidation of girinimbine led to (−)-trans-dihydroxygirinimbine and the assignment of its absolute configuration
Dieser Beitrag ist mit Zustimmung des Rechteinhabers aufgrund einer (DFG-geförderten) Allianz- bzw. Nationallizenz frei zugänglich

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Gruner, Konstanze K., Thomas Hopfmann, Kazuhiro Matsumoto, Anne Jäger, Tsutomu Katsuki y Hans-Joachim Knölker. "Efficient iron-mediated approach to pyrano[3,2-a]carbazole alkaloids - first total syntheses of O-methylmurrayamine A and 7-methoxymurrayacine, first asymmetric synthesis and assignment of the absolute configuration of (−)-trans-dihydroxygirinimbine". Royal Society of Chemistry, 2011. https://tud.qucosa.de/id/qucosa%3A27777.

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Iron-mediated oxidative cyclisation provides an efficient approach to pyrano[3,2-a]carbazole alkaloids. Thus, improved routes to girinimbine and murrayacine as well as the first total syntheses of O-methylmurrayamine A and 7-methoxymurrayacine are reported. Asymmetric epoxidation of girinimbine led to (−)-trans-dihydroxygirinimbine and the assignment of its absolute configuration.
Dieser Beitrag ist mit Zustimmung des Rechteinhabers aufgrund einer (DFG-geförderten) Allianz- bzw. Nationallizenz frei zugänglich.

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Capítulos de libros sobre el tema "Absolute asymmetric catalysis"

Taber, Douglass F. "The Li Synthesis of (–)-Fusarisetin A". En Organic Synthesis. Oxford University Press, 2015. http://dx.doi.org/10.1093/oso/9780190200794.003.0097.

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Fusarisetin A 3 is an intriguing inhibitor of cell migration and invasion that is not itself cytotoxic. Ang Li of the Shanghai Institute of Organic Chemistry developed (J. Am. Chem. Soc. 2012, 134, 920) a total synthesis of (–)-fusarisetin A, demonstrating that the natural material had the absolute configuration opposite to that originally assigned. A key step in the synthesis was the highly diastereoselective cyclization of 1 to 2. The absolute configuration of 1 and so of synthetic 3 was derived from commercial citronellol, which is prepared on an industrial scale by asymmetric synthesis. To this end, the reagents 6 and 8 were required. The β-ketothio ester 6 was prepared from the Meldrum’s acid 4 and the phosphonate 8 was derived from methyl sorbate 7. The acetal of citronellal 9 was ozonized with reductive work-up to give the alcohol 10. Protection followed by hydrolysis gave the aldehyde 11, which was condensed with 8 to give the triene 12. Deprotection followed by oxidation delivered an aldehyde, which was condensed with 6 to give the Diels-Alder precursor 1. With BF3 • OEt2 catalysis, the Diels-Alder cycloaddition proceeded under mild conditions, –40oC for 40 min, leading to 2 as a single diastereomer. Comparable intramolecular Diels-Alder cyclizations with single carbonyl activation gave mixtures of diastereomers. The alcohol 13 was prepared by transesterification of 2 with trifluoroethanol. Activation with MsCl led directly to the kinetic O-alkylation product 14. Following the precedent of Trost (J. Am. Chem. Soc. 1980, 102, 2840), exposure to a Pd catalyst smoothly converted 14 into 15 as the desired diastereomer. Condensation of the ester 15 with the amine 16 gave the diene 17. Selective oxidation of the monosubstituted alkene under Wacker conditions gave the ketone, which was reduced selectively by the Luche protocol to the alcohol 18. Exposure of 18 to NaOCH3 initiated Dieckmann cyclization, leading to (–)-fusarisetin A 3.

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Taber, Douglass F. "C–H Functionalization: The Maimone Synthesis of Podophyllotoxin". En Organic Synthesis. Oxford University Press, 2017. http://dx.doi.org/10.1093/oso/9780190646165.003.0021.

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Matthias Beller of the Universität Rostock developed (Angew. Chem. Int. Ed. 2014, 53, 6477) a Rh catalyst for the acceptorless dehydrogenation of an alkane 1 to the alkene 2. Bhisma K. Patel of the Indian Institute of Technology Guwahati effected (Org. Lett. 2014, 16, 3086) oxidation of cyclohexane 3 and 4 to form the allylic benzoate 5. Justin Du Bois of Stanford University devised (Chem. Sci. 2014, 5, 656) an organocatalyst that mediated the hydroxylation of 6 to 7. Vladimir Gevorgyan of the University of Illinois, Chicago hydrosilylated (Nature Chem. 2014, 6, 122) 8 to give an intermediate that, after Ir-catalyzed intramolecular C–H functionalization followed by oxidation, was converted to the diacetate 9. Sukbok Chang of KAIST used (J. Am. Chem. Soc. 2014, 136, 4141) the methoxime of 10 to direct selective amination of the adjacent methyl group, leading to 11. John F. Hartwig of the University of California, Berkeley effected (J. Am. Chem. Soc. 2014, 136, 2555) diastereoselective Cu-catalyzed amination of 12 with 13 to make 14. David W. C. MacMillan of Princeton University accomplished (J. Am. Chem. Soc. 2014, 136, 6858) β-alkylation of the aldehyde 15 with acrylonitrile 16 to give 17. Yunyang Wei of the Nanjing University of Science and Technology alkenylated (Chem. Sci. 2014, 5, 2379) cyclohexane 3 with the styrene 18, leading to 19. Bin Wu of the Kunming Institute of Botany described (Org. Lett. 2014, 16, 480) the Pd-mediated cyclization of 20 to 21. Similar results using Cu catalysis were reported (Angew. Chem. Int. Ed. 2014, 53, 3496, 3706) by Yoichiro Kuninobu and Motomu Kanai of the University of Tokyo and by Haibo Ge of IUPUI. Jin-Quan Yu of Scripps La Jolla constructed (J. Am. Chem. Soc. 2014, 136, 5267) the lactam 24 by γ-alkenylation of the amide 22 with 23, followed by cyclization. Philippe Dauban of CNRS Gif-sur-Yvette prepared (Eur. J. Org. Chem. 2014, 66) the useful crystalline chiron 27 by asymmetric amination of the enol triflate 26 with 25. Matthew J. Gaunt of the University of Cambridge showed (J. Am. Chem. Soc. 2014, 136, 8851) that the phenylative cyclization of 28 with 29 to 30 proceeded with near-perfect retention of absolute configuration.

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"α-Substitution in Carbonyl Compounds and Derivatives". En The Chemistry of Carbonyl Compounds and Derivatives, 201–73. The Royal Society of Chemistry, 2022. http://dx.doi.org/10.1039/9781837670888-00201.

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The discussion on the reactivity of carbonyl compounds is expanded by incorporating reactions which involve the position alpha to the carbonyl carbon. The α-alkylation of carbonyl compounds, enamines, and azaenolates derived from imines is presented and the regio- and stereochemical aspects are considered. We address the formation of enolates from aldehydes and ketones, and the corresponding aza analogs from imines and nitriles, emphasizing the structural and experimental conditions, which may discriminate between kinetic and thermodynamic products. Particular attention is paid to the aldol reaction of lithium and boron enolates to control the relative stereochemistry of the products. The use of chiral auxiliaries and catalytic asymmetric versions, such as the organocatalyzed aldol reaction, for the control of the absolute configuration of the products is introduced. The Mukaiyama, Mannich, and halogenation reactions are also discussed in their racemic and asymmetric versions. The role of reactions discussed in the biosynthesis of natural products is exemplified.

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Taber, Douglass. "Stereocontrolled Construction of C-N Rings: The Vanderwal Synthesis of Norfluorocurarine". En Organic Synthesis. Oxford University Press, 2011. http://dx.doi.org/10.1093/oso/9780199764549.003.0056.

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Forrest E. Michael of the University of Washington described (Organic Lett. 2009, 11, 1147) the Pd-catalyzed aminative cyclization of 1 to the differentially-protected diamine 3. Peter Somfai of KTH Chemical Science and Engineering observed (Organic Lett. 2009, 11, 919) that [1,2]-rearrangement of 4 proceeded to deliver 5 with near-perfect maintenance of enantiomeric excess. Tushar Kanti Chakraborty of the Central Drug Research Institute, Lucknow applied (Tetrahedron Lett. 2009, 50, 3306) the Ti(III) reduction of epoxides to the Sharpless-derived ether 6, leading to the pyrrolidine 7. Chun-Jiang Wang of Wuhan University devised (Chem. Commun. 2009, 2905) a silver catalyst that directed the absolute sense of the dipolar addition of 9 to 8 to give 10. Homoallyic azides such as 11 are readily prepared in high enantiomeric excess from the corresponding alcohol. Bernhard Breit of Albert-Ludwigs-Universität, Freiburg and André Mann of the Faculté de Pharmacie, Illkirch showed (Organic Lett. 2009, 11, 261) that Rh-mediated hydroformylation could be effected in the presence of the azide. Subsequent reduction delivered the piperidine 12. Jan-E. Bäckvall of Stockholm University applied (J. Org. Chem. 2009, 74, 1988) the protocol for dynamic kinetic asymmetric transformation (DYKAT) that he had developed to the cyanodiol 13. Remarkably, a single enantiomerically- pure diasteromer emerged, which he carried on to 14. Xiaodong Shi of West Virginia University found (Organic Lett. 2009, 11, 2333) that the stereogenic center of 17, even though it ended up outside the ring, directed the absolute configuration of the other centers of 18 as they formed. Jan Vesely of Charles University and Albert Moyano and Ramon Rios of the Universitat de Barcelona established (Tetrahedron Lett. 2009, 50, 1943) that an organocatayst directed the absolute configuration in the addition of 19 to 20 to give 21. Osamu Tamura of Showa Pharmaceutical University effected (Organic Lett. 2009, 11, 1179) cyclization of the malic acid-derived amide 22 to give 23 with high diastereocontrol.

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Taber, Douglass F. "Synthesis of Naturally Occurring Cyclic Ethers: Boivivianin B (Murakami), SC- Δ 13 -9-IsoF (Taber), Brevisamide (Panek, Lindsley,Ghosh), Gambierol (Mori)". En Organic Synthesis. Oxford University Press, 2013. http://dx.doi.org/10.1093/oso/9780199965724.003.0050.

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The challenge of controlling the relative and absolute configuration of highly substituted cyclic ether-containing natural products continues to stimulate the development of new synthetic methods. Masahiro Murakami of Kyoto University showed (J. Org. Chem. 2009, 74, 6050) that Rh-mediated addition of an aryl boronic acid to 1 proceeded with high syn diastereocontrol, giving 3. This set the stage for Au-mediated rearrangement, leading to 4. We found (J. Org. Chem. 2009, 74, 5516) that asymmetric epoxidation of 5 followed by exposure to AD-mix could be used to prepare each of the four diastereomers of 6. We carried 6 on the isofuran 7, using a stereodivergent strategy that allowed the preparation of each of the 32 enantiomerically pure diastereomers of the natural product. Following up on the synthesis of brevisamide 16 described (Organic Highlights, November 16, 2009) by Kazuo Tachibana of the University of Tokyo, three groups reported alternative total syntheses. James S. Panek of Boston University prepared (Organic Lett. 2009, 11, 4390) the cyclic ether of 16 by addition of the enantiomerically pure silane 9 to 8. Craig W. Lindsley of Vanderbilt University used (Organic Lett. 2009, 11, 3950) SmI2 to effect the cyclization of 11 to 12. Arun K. Ghosh of Purdue University employed (Organic Lett. 2009, 11, 4164) an enantiomerically pure Cr catalyst to direct the absolute configuration in the hetero Diels-Alder addition of 14 to 13. Rubottom oxidation of the enol ether so formed led to the α-hydroxy ketone 15. Yuji Mori of Meijo University described (Organic Lett. 2009, 11, 4382) the total synthesis of the Gambierdiscus toxicus ladder ether gambierol 19. A key strategy, used repeatedly through the sequence, was the exo cyclization of an epoxy sulfone, illustrated by the conversion of 17 to 18. The epoxy sulfones were prepared by alkylating the anions derived from preformed epoxy sulfones such as 20.

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Taber, Douglass F. "C–O Ring Construction: Sauropus Hexoside (Xie/Wu), (+)-Ipomeamarone (Usuki), Decytospolide A (Fujioka), Cytospolide P (Goswami), (+)-Didemniserinolipid B (Tong), Gymnothelignan N (She)". En Organic Synthesis. Oxford University Press, 2017. http://dx.doi.org/10.1093/oso/9780190646165.003.0051.

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A range of biological activity was observed for the group of 3,6-anhydro-2-deoxy hexosides, of which 3 is representative, isolated from Sauropus rostratus. Wei-Jia Xie and Xiao-Ming Wu of China Pharmaceutical University prepared (Org. Lett. 2014, 16, 5004) 3 by the dealkylative cyclization of 1 to 2. (+)-Ipomeamarone 6 is a phytoalexin isolated from mold-damaged sweet potatoes. Yoshinosuke Usuki of Osaka City University assembled (Chem. Lett. 2014, 43, 1882) 6 by the diastereoselective cyclization of 4 to 5. Hiromichi Fujioka of Osaka University protected (Org. Lett. 2014, 16, 3680) the enone of 7 by the conjugate addition of triphenylphosphine. Diastereoselective reduction of the other ketone followed by deprotection of the enone and cyclization led to 8, that was hydrogenated to decytospolide A 9. En route to cytospolide P 12, Rajib Kumar Goswami of the Indian Association for the Cultivation of Science had planned (J. Org. Chem. 2014, 79, 7689) the ring-closing metathesis of 10. This failed, but cyclization of the corresponding silyl ether to 11 was successful with the second-generation Hoveyda catalyst. Rongbiao Tong of the Hong Kong University of Science and Technology set (J. Org. Chem. 2014, 79, 6987) the absolute configuration of (+)-didemniserinolipid B 15 by Sharpless asymmetric osmylation of the alkene 13. Oxidative Achmatowicz rearrangement/bicycloketalization then delivered 14. Xuegong She of Lanzhou University observed (Org. Lett. 2014, 16, 4440) remarkable diastereoselectivity in the reductive cyclization of 16 to 17. Oxidation of 17 led to regioselective cyclization to gymnothelignan N 18.

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