HETEROCYCLES
An International Journal for Reviews and Communications in Heterocyclic ChemistryWeb Edition ISSN: 1881-0942
Published online by The Japan Institute of Heterocyclic Chemistry
Regular Issue
Vol. 41, No. 3, 1995
Published online:
■ On the Chemistry of the 18-Deoxycytochalasin H, HIV-1 Protease Inhibitor, L-696,474. 1: Degradation Studies Leading to the 2-Isoindolone Core
B. Moon Kim* and James P. Guare
*Department of Medicinal Chemistry, Merck Research Laboratories, West Point, PA 19486, U.S.A.
Abstract
Degradation studies of 18-deoxycytochalasin H, a 3 μM HIV-1 protease inhibitor, led to a 2-isoindolone core with conservation of functional groups on the bicyclic ring.
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■ On the Chemistry of the 18-Deoxycytochalasin H, HIV-1 Protease Inhibitor, L-696,474. 2: Novel Ring Annulations
B. Moon Kim*, James P. Guare, and Steven M. Pitzenberger
*Department of Medicinal Chemistry, Merck Research Laboratories, West Point, PA 19486, U.S.A.
Abstract
Unprecedented annulation of the 11-membered ring portion of 18-deoxycytochalasin H, a 3μM inhibitor of HIV-1 protease, has been observed furnishing a novel tetracyclic cytochalasin (5). Subsequent desilylation of 5 provided yet another set of new tetracyclic cytochalasin derivatives.
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■ Asymmetric Synthesis of Celacinnine Utilizing Optically Active Vinyl Sulfoxides
Nobuhiro Itoh, Haruo Matsuyama*, Masao Yoshida, Nobumasa Kamigata, and Masahiko Iyoda*
*Department of Chemistry, Faculty of Science, Tokyo Metropolitan University, Hachioji, Tokyo 192-03, Japan
Abstract
First asymmetric synthesis of celacinnine (10) was achieved from the nine-membered azalactam, 3-phenyl-4-azaoctanelactam (6), which was synthesized by the addition of piperidazine (4) to optically active vinyl sulfoxides (3).
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■ Conformational Preference in Benzyloxy- and Siloxy-substituted Thianes, Thiane 1-Oxides, and Thiane 1,1-Dioxides
Yoshimitsu Nagao*, Michimasa Goto, Kiyoshi Kida, and Motoo Shiro
*Faculty of Pharmaceutical Sciences, The University of Tokushima, Sho-machi, Tokushima 770, Japan
Abstract
Conformer ratios in 4-benzyloxy- and 4-siloxy-substituted thianes, cis- and trans-thiane 1-oxides, thiane 1,1-dioxides, and dihydrothiines were revealed on the basis of their low temperature 1H nmr analysis. Extreme benzyloxy- and siloxy-axial (or -pseudoaxial) conformer preferences in trans-thiane 1-oxides, thiane 1,1-dioxides, and dihydrothiines were clearly demonstrated.
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■ Concise Enantioselective Synthesis of (+)-Asperlin by Application of the Sharpless Kinetic Resolution to 2-Furylmethanol Derivatives Bearing Alkenyl Moiety on the Side Chain
Toshio Honda*, Nobuko Sano, and Kazuo Kanai
*Institute of Medicinal Chemistry, Hoshi University, Ebara 2-4-41, Shinagawa, Tokyo 142, Japan
Abstract
A reaction of (±)-(E)-1-(2-furyl)but-2-en-1-ol (1) under the Sharpless asymmetric oxidation condition using 30 mol% of D-(-)-diisopropyl tartrate (DIPT), 25 mol% of titanium tetraisopropoxide and 120 mol% of tert-butyl hydroperoxide (TBHP) afforded the (S)-epoxide (3), in 42% yield with high optical purity, which was further converted into an antitumour antibiotic, asperlin (10).
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■ Reactions of 8H-Furo[3,4-d]dibenz[b,f]azepine and 9H-Tribenz[b,d,f,]azepine with t-Butyl Hypochlorite and Silver Trifluoroacetate. Attempts to Form a Long-lived Aromatic Nitrenium Ion
Holly C. Axtell, Kathleen B. McHugh, and Michael C. Cann*
*Department of Chemistry, University of Scranton, Scranton, PA 18510-4626, U.S.A.
Abstract
Attempts to prepare aromatic and thus potentially long-lived nitrenium ions from 8H-furo[3,4-d]dibenz[b,f]azepine (19) and 9H-tribenz[b,d,f]azepine (34) were unsuccessful. Reaction of 19 with t-butyl hypochlorite results in chlorination of the furan ring (25), while reaction of 19 with silver trifluoroacetate forms a mixture of the cis- and trans-dimethoxydihydrofurans (32) and (33). Reaction of 34 with t-butyl hypochlorite leads to a mixture of mono-, di- and trichloroazepines (37-42). The reaction of silver trifluoroacetate with 34 yields silver metal and unreacted 34.
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■ Radical β-Fragmentation of Bicyclic[3.3.0]carbinolamides: Synthesis of Five- and Eight-membered Cyclic Imides
Rosendo Hernández, Daniel Melián, Thierry Prangé, and Ernesto Suárez*
*Instituto de Productos Naturales y Agrobiología del C.S.I.C., Garretera de La-Esperanza, 38206- La Laguna, Tenerife, Spain
Abstract
The influence of 4-alkyl or 4-aryl substituents in the regioselectivity of the β-fragmentation of carbinolamidyl redicals generated from the corresponding carbinolamides (7-13) by irradiation with visible light in the presence of (diacetoxyiodo)benzene and iodine is described. In the case of the less hindered carbinolamides 1-hydroxyazabicyclo[3.3.0]octan-3-one (7) and 4-(2’-phenylethyl)-1-hydroxyazabicyclo[3.3.0]octan-3-one (8) important amounts of 8-membered cyclic imides were obtained together with the expected 5-membered imides (succinimides).
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■ Synthesis of 2-Substituted 1,3-Benzothiazoles by Aza-Wittig Reaction of 2-Methylthio-N-triphenylphosphoranylideneaniline with Acid Chlorides
Masahiko Takahashi* and Masaru Ohba
*Department of Materials Science, Faculty of Engineering, Ibaraki University, Hitachi, Ibaraki 316, Japan
Abstract
The aza-Wittig reaction of 2-methylthio-N-triphenylphosphoranylideneaniline (2) with acid chlorides (3) in refluxing benzene or toluene afforded 2-substituted 1,3-benzothiazoles (6).
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■ A Convenient Synthesis of Pyrido[3,2-b][1,4]bensothiazine Derivatives via Oxidative Ring Closure of 3-Substituted 6-[N-(2-Mercaptophenyl)]aminopyridines
Ji-Wang Chern* and Kuo-Rong Wu
*Medical Laboratories and Institute of Pharmacy, National Defense Medical Center, P.O. Box 90048-512, Taipei, Taiwan, R.O.C.
Abstract
3-Substituted pyrido[3,2-b][1,4]benzothiazines were prepared either by heating the disulfide derivatives, which were obtained by a treatment of 3-substituted 6-[N-(2-mercaptophenyl)]aminopyridines with diethyl azodicarboxylate (DEAD) or NBS in DMF at room temperature under the basic conditions or directly by heating the reaction mixture 3-substituted 6-[N-(2-mercaptophenyl)]aminopyridines.
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■ Reaction of [2.2]Paracyclophane with 4-Phenyl-1,2,4-triazoline-3,5-dione
Kiyoshi Matsumoto,* Mitsuo Toda, and Akikazu Kakehi
*Graduate School of Human and Environmental Studies, Kyoto University, Kyoto 606-01, Japan
Abstract
Diels-Alder reaction of [2.2]paracyclophane with 4-phenyl-1,2,4-triazoline-3,5-dione was reinvestigated. The stereochemistry of the 1:2 adduct was established by the X-ray analysis, the reaction taking place in the sence of 4,7:13,16-cross bridge additions rather than 4,7:12,15-parallel bridge additions.
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■ Synthesis of 2-(4-Aryl-1E,3E-butadienyl)benzoxazoles by the Horner-Wadsworth-Emmons Reaction
Takatoshi Kosaka and Toshio Wakabayashi*
*Tsukuba Research Institute, Sandoz Pharmaceuticals, LTD., 8 Ohkubo, Tsukuba, Ibaraki 300-33, Japan
Abstract
2-(4-Aryl-1E,3E-butadienyl)benzoxazole derivatives were synthesized by the Horner-Wadsworth-Emmons reaction of 2-phosphorylmethylbenzoxazoles with cinnamaldehydes in fair to good yield.
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■ Synthesis of Substituted Pyrazolo[3,4-b]- and Pyrazolo[4,3-c]phenothiazine Derivatives
Gérard Boyer*, Jean Pierre Galy, and Jacques Barbe
*URA-CNRS 1411, Laboratoire de Valorisation de la Chimie Fine, case 552, Université Aix-Marseille III, avenue Escadrille Normandie-Niemen, 13397 Marseille Cedex 20, France
Abstract
The synthesis of new pyrazolo[b]- and [c]phenothiazines by the Bernthsen thionation of N-arylindazoles obtained using organometalic compounds is reported.
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■ Synthesis of 6-Substituted Imidazo[4,5-c]pyrazole-5-thiones
Chiara B. Vicentini, Valeria Ferretti, Augusto C. Veronese, Mario Guarneri, Maurizio Manfrini, and Paolo Giori*
*Dipartimento di Scienze Farmaceutiche, Università di Ferrara, 44100, Ferrara, Italy
Abstract
Treatment of diaminopyrazole derivatives (2) wityh thiophosgene afforded selectively the isothiocyanatopyrazoles (3). Heating of 3 in pyridine gave the imidazo[4,5-c]pyrazole-5-thiones (4).
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■ C-Nucleosides. 24. Synthesis of Pyrazolo[1,5-a]pyrimidine C-Nucleoside through Cyclocondensation of Enaminone Glycoside with Aminopyrazoles
Isamu Maeba*, Yasufumi Nishiyama, Shigeyuki Kanazawa, and Akiko Sato
*Faculty of Pharmacy, Meijo University, Tempaku, Nagoya 468, Japan
Abstract
A versatile intermediate enaminone glycoside (1) for C-nucleoside synthesis was treated with aminopyrazoles to give pyrazolo[1,5-a]pyrimidine C-nucleosides.
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■ Pyrrolothieno[1,4]diazepines Part 1 : Synthesis and Study of the Reaction Pathway
Michel Boulouard, Sylvain Rault, Patrick Dallemagne, and Max Robba*
*Centre d’Etudes et de Recherche sur le Médicament de Normandie, U. F. R. des Sciences Pharmaceutiques, 1, rue Vaubénard, 14032 CAEN cedex, France
Abstract
Synthesis of 5,6-dihydro-4-oxo-4H-pyrrolo[1,2-a]thieno[3,2-f][1,4]diazepines is achieved starting from 2-(2-formyl-1H-pyrrol-1-yl)-3-thiophenecarbonitrile. Reaction pathway is demonstrated via isolation of intermediates involved in the synthetic reaction.
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■ Synthesis of 3'-Amino-3'-deoxyadenosine from Levoglucosenone
Hideyuki Kuno*, Shigeo Niihata, Takashi Ebata, and Hajime Matsushita
*Life Science Research Laboratory, Japan Tobacco Inc., 6-2 Umegaoka, Aoba-ku, Yokohama, Kanagawa 227, Japan
Abstract
A synthesis of 3’-amino-3’-deoxyadenosine (2) was developed by utilizing levoglucosenone (1) as a starting material through regio- and stereoselective cis-oxyamination of the carbon-carbon double bond.
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■ Synthesis and Reactions of Lithiated Monocyclic Azoles Containing Two or More Hetero-Atoms. Part V: Isothiazoles and Thiazoles
Brian Iddon*
*The Ramage Laboratories, Department of Chemistry and Applied Chemistry, University of Salford, Salford M5 4WT, England
Abstract
The metallation and halogen → metal exchange reactions of isothiazoles (1,2-thiazoles) and thiazoles (1,3-thiazoles) and the reactions of the resulting organometallic derivatives, particularly lithiated derivatives, are reviewed comprehensively.