HETEROCYCLES
An International Journal for Reviews and Communications in Heterocyclic ChemistryWeb Edition ISSN: 1881-0942
Published online by The Japan Institute of Heterocyclic Chemistry
Special Issue
Teruaki Mukaiyama's Special Issues, Vol. 52, No. 3, 2000
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■ Synthesis and Reaction of Chiral 4,5-Disubstituted 2-Oxazolidinones from 3-Ethoxy-6-(N-alkyl-N-tert-butoxycarbonyl)aminohexa-2,4-dienoates in the Presence of Concentrated Sulfuric Acid Supported on Silica Gel
Tomikazu Kawano, Kenji Negoro, Hajime Nitta, and Ikuo Ueda*
*The Institute of Scientific and Industrial Research, Osaka University, Mihogaoka, Ibaraki, Osaka 567-0047, Japan
Abstract
Reaction of chiral 3-ethoxy-6-(N-alkyl-N-tert-butoxycarbonyl)-aniino-hexa-2,4-dienoates (3) and related compounds with 97% concentrated sulfuric acid supported on silica gel proceeded stereo- and regio-selectively to yield chiral 4,5-disubstituted N-alkyl-2-oxazolidinones (7). Under the limited conditions, 7 were converted into N-alkyl-2-pyrrolylacetates (8) and 2-oxazolidinone derivatives (12) which may serve as a chiral auxiliary.
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■ A Facile Synthesis of 5-Substituted 2-Furyl-, 2-Thienyl- and 2-Pyrrolylacetates by Cyclodehydration of γ-Functionalized α,β-Unsaturated Ketones
Tomikazu Kawano, Toru Ogawa, Saiful Md. Islam, and Ikuo Ueda*
*The Institute of Scientific and Industrial Research, Osaka University, 8-1. Mihogaoka, Ibaraki, Osaka 567-0047, Japan
Abstract
Synthesis of 5-substituted 2-furyl-, 2-thienyl- and 2-pyrrolyl-acetates is achieved by acid-catalyzed cyclodehydration of γ-hydroxy (γ-acetylthio and γ-amino)-α,β-unsaturated ketones generated from ethyl 6-substituted 3-ethoxy-6-hydroxy-(6-acetylthio and 6-amino)hexa-2,4-dienoates which are easily accessible from α-functionalized carbonyl compounds and Wittig reagents.
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■ Investigations Directed at the Total Synthesis of Ouabain. Lessons Learned fromDegradation Studies
Larry E. Overman* and Paul V. Rucker
*516 Rowland Hall, University of California, Irvine, California 92697-2025, U.S.A.
Abstract
A procedure has been developed for transforming pentacyclic Heck product (8) to enone (10), an intermediate having appropriate functionality for future elaboration of the Cl and C3 diol functionality of ouabagenin. The plant-derived cardiac glycoside ouabain has been degraded to analogs (17) and (20) that contain, respectively, a Δ9,11 double bond and C17 nitrile. These intermediates should be useful in future efforts to develop chemistry for functionalizing the Δ9,11 double bond of 8 to incorporate Cli oxidation and for elaborating the β C17 nitrile of this advanced synthetic intermediate to a β butenolide.
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■ A Highly Efficient Synthetic Route to (-)-Furaquinocin C
Amos B. Smith, III*, José Pérez Sestelo, and Peter G. Dormer
*Department of Chemistry, University of Pennsylvania, 231 South 34th Street Philadelphia, PA 19104, U.S.A.
Abstract
The first total synthesis of (-)-furaquinocin C, a member of the furaquinocin family of cytotoxic antibiotics, has been achieved. Central features of the successful synthetic strategy include Diels-Alder construction of the furanonaphthoquinic skeleton and sequential cuprate-mediated conjugate additions to an α,β-unsaturated lactone. The synthetic route proved remarkably efficient requiring only six steps from (R)-(+)-angelicalactone, and utilizing a mere four reaction vessels. This stereospecific construction of (-)-furaquinocin C confirms earlier assignments of absolute and relative stereochemistry for the furaquinocins and also constitutes completion of a formal synthesis of (-)-furaquinocin F.
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■ Reactivity of 2',3'-Anhydro Pyrimidine Nucleosides toward Trimethylaluminum
Kosaku Hirota,* Hideki Takasu, and Hironao Sajiki
*Labolatory of Medicinal Chemistry, Gifu Pharmaceutical University, 6-1 Mitahora-higashi 5-chome, Gifu 502-8585, Japan
Abstract
Treatment of 2’,3’-anhydro pyrimidine nucleoside derivatives (1) with trimethylaluminum afforded 1-(3-deoxy-3-methyl-β-D-arabinofuranosyl)pyrimidine derivatives (2) and 1-(2-deoxy-2-methyl-β-D-xylofuranosyl)pyrimidine derivatives (3) as a mixture in approximately 2 : 1 - 3 : 1 ratio via ring-opening of the epoxide involving the nucleophilic attack of trimethylaluminum at the 3’ or 2’-position of 1.
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■ Stereoselective Aldol Addition of a Chiral Glycine Enolate Synthon to Heteroaromatic Aldehydes
Piero Dalla Croce,* Raffaella Ferraccioli, Concetta La Rosa, and Enrica Pizzatti
*Dipartimento di Chimica Organica e Industriale, Centro C. N. R., V. Venezian 21 I-20133 Milano, Italy
Abstract
The stereocontrolled addition of (2S)-(+)-2,5-dihydro-3,6-dimethoxy-2-isopropylpyrazine (1) to heterocyclic aldehydes (2) gives mainly a mixture of syn/anti isomers (3) and (4) whose steric configuration was assigned on the basis of spectroscopic data and accepted model for aldol condensation of 1. The possible conversion of adducts to threo β-substituted heteroaromatic serines is demonstrated.
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■ The Structure and Antimalarial Activity of Some 1,2,4-Trioxanes, 1,2,4,5-Tetroxanes, an Bicyclic Endoperoxides. Implications for the Mode of Action
Charles W. Jefford,* Jean-Claude Rossier, and Wilbur K. Milhous
*Department of Organic Chemistry, University of Geneva, 1211 Geneva 4, Switzerland
Abstract
The mode of antimalarial action of cis-fused cyclopenteno-1,2,4-trioxanes (7-13), dispiro-1,2,4,5-tetroxanes (14-17), and bridged bicyclic endoperoxides (18-22) was examined by systematically changing substituents at positions remote from the O-O bond. It is concluded that peroxides of high activity (7-11, 14-15, 18, and 19) are able to intimately dock on heme and rearrange efficiently to an ethyl radical which kills the parasite by alkylation. Dimethyl substituents on the spirocyclohexane ring in the trioxanes (12 and 13) and tetroxane (16) diminish activity by hampering either docking or the reactivity of a C-centered radical. Endoperoxides derived from methylnaphthalenes (20-22) are inactive owing to their inability to generate an ethyl radical.
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■ Preparation of Optically Active 15-Epoxy-α-linolenic Acids and Their Anti-Rice Blast Fungus Activities
Tadahiro Kato,* Toshio Nakai, Takayuki Ishimatu, Masahiro Hoshikawa, and Tsuneo Namai
*Department of Chemistry, Faculty of Science, Science University of Tokyo, Kagurazaka 1-3, Shinjuku-ku, Tokyo 162-8601, Japan
Abstract
By the action of NBS in aq. DME, α-linolenic acid was oxidized to 15-bromo-16-hydroxy-α-linolenic acid in 35% conversion yield. The bromohydrin was treated with lipase-PS and vinyl acetate to give the resolved acetate and bromohydrin. (15S,16R)- and (15R,16S)-Epoxy-α-linolenic acids were prepared from the corresponding resolved products. A comparison of anti-rice blast fungus activities showed that an unnatural epoxide is stronger than the natural epoxide.
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■ Optical Resolution of Fragrant Lactones
Hiroyuki Nohira,* Keiko Mizuguchi, Toru Murata, Yuko Yazaki, Miho Kanazawa, Yoshio Aoki, and Misako Nohira
*Department of Applied Chemistry, Faculty of Engineering, Saitama University, Urawa, Saitama 338-8570, Japan
Abstract
Optical resolution of six chiral fragrant lactones (δ-jasmine lactone, massoia lactone, tuberolactone, pentynyllactone, δ-decalactone, and γ-nonalactone) was investigated by means of either the diastereomeric salt formation method or the diastereomeric amide formation method. Using these procedures, we obtained each enantiomer from five of the six lactones, except for massoia lactone. All five lactones were obtained in a good yield and with high optical purity. Sensoric characteristics on both enantiomers and racemic modification of four lactones are given.
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■ Synthesis of Fused Systems in the Isoquinoline Series: Oxazolo- and Pyrrolo[3,2-c]isoquinolines
Jean-François Brière, Georges Dupas,* Guy Quéguiner, and Jean Bourguignon
*Laboratoire de Chimie Organique Fine et Hétérocyclique de L’IRCOF , UPRESA 6014, CNRS, Institut National des Sciences Appliquées de Rouen, BP 08, 76131 Mont Saint Aignan Cedex, France
Abstract
In order to synthesize the pyrrolo[3,2-c]isoquinoline structure, three different routes starting from readily available isoquinolines were tried. The ring closure reaction of a malonic derivative of 4-amino-3-bromoisoquinoline led to an oxazolo[3,2-c]isoquinoline instead of the target molecule. This latter was obtained via Sonagashira coupling reaction followed by ring closure under basic conditions. A study of the lithiation of the N-sulfonated pyrrolo[3,2-c]isoquinoline was undertaken. After optimization of the lithiation conditions, various 2-substituted pyrrolo[3,2-c]isoquinolines were obtained and their oxidation reactions studied.
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■ Unexpected Reaction of 3-Phenyl-3-chloro-2-oxopropanoic Acid Derivatives with Sodium Azide. A Novel Synthesis of Highly Functionalized Oxazolines
Vakhid A. Mamedov, Aidar T. Gubaidullin, Igor A. Litvinov, and Sadao Tsuboi*
*Department of Environmental Chemistry and Materials, Okayama University, 2-1-1 Tsushima-naka, Okayama 700-8530, Japan
Abstract
The reaction of 3-phenyl-3-chloro-2-oxopropanoic acid derivatives with sodium azide proceeded unexpectedly with the formation of oxazolines via intermediately forming α-azido- and/or α-imino ketones.
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■ Synthesis of 5-Diphenylphosphinoyl-2,3-dihydropyran-4-ones
Tatsuo Okauchi,* Hironobu Nagamori, Ryouji Kouno, Junji Ichikawa, and Toru Minami*
*Department of Applied Chemistry, Faculty of Engineering, Kyushu Institute of Technology, 1-1 Sensuicho, Tobata, Kitakyushu, 804-8550, Japan
Abstract
5-Diphenylphosphinoyl-2,3-dihydropyran-4-ones are readily prepared from the corresponding 5-diphenyiphosphinoyl-1-buten-3-yne under mild acidic conditions. The phosphorus substituted pyrones are converted to more substituted pyrones via 1,4-addition of copper reagents followed by Homer-Wittig reaction.
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■ Stereocontrolled Syntheses of Unsymmetrically Substituted Furofuran Lignans
Hiroshi Ohmizu,* Tsuyoshi Ogiku, and Tameo Iwasaki
*Discovery Research Laboratory, Tanabe Seiyaku Co., Ltd., 3-16-89 Kashima, Yodogawa, Osaka 532-8505, Japan
Abstract
Novel and efficient methods for the syntheses of the simple furofuran lignans (I) and the bislactone furofuran lignans (III) are comprehensively described. Asymmetric synthesis of the series (I) based on the enantioselective Michael addition reaction is also described
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■ Perfluorinated Acyl(aroyl)pyruvates as Building Blocks for the Synthesis of Heterocycles
Viktor I. Saloutin,* Yanina V. Burgart, C. Oliver Kappe, and Oleg N. Chupakhin
*Institute of Organic Synthesis, Urals Division, Russian Academy of Sciences, 20, S. Kovalevskaya st., Ekaterinburg, GSP-147, 620219, Russia
Abstract
Data on the synthesis and chemical transformations of 3-polyfluoroacyl- and 3-pentafluorobenzoylpyruvates and their derivatives are reviewed. Reactions giving fluorinated heterocycles and syntheses based on these transformations are discussed.
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■ Origin of π-Facial Diastereoselection in Carbonyl Addition. Application of the Exterior Frontier Orbital Extension Model to 1,3-Diheteran-5-ones (Heteroatom = O, S)
Shuji Tomoda,* Daisuke Kaneno, and Takatoshi Senju
*Department of Life Science, Graduate School of Arts and Sciences, The University of Tokyo, Komaba, Meguro-ku, Tokyo 153-8902, Japan
Abstract
The exterior frontier orbital extension model (the EFOE Model) strongly suggested that reversal of π-facial diastereoselection in nucleophilic additions of 1,3-diheteran-5-ones (heteroatom = O or S) may originate from the unique groundstate conformation and the π-facial difference in the LUMO extension around the carbonyl carbon rather than from transition state effects. Intrinsic reaction coordinate (IRC) and natural bond orbital (NBO) analyses of transition states of LiAlH4 reduction of these ketones have strongly indicated that the transition state effects (the torsional strain of the ketone moieties and the antipenpianar effects involving the incipient bond proposed by the conventional theoretical models for π-facial diastereoselection ; the Felkin-Anh model and the Cieplak model) are not responsible for facial selection.