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. 32, No. 1, 1991
Published online:
■ 1,3-Dipolar Cycloadditions of N,α-Diphenylnitrone to the 4,5-Positions of 1H-Azepine and 1H-1,2-Diazepine Derivatives: Formation of endo- and exo-Type Cycloadducts and Computer-assisted Line Shape Simulation of the Nmr spectra of the Adducts
Katsuhiro Saito,* Akihiro Yoshino, and Kensuke Takahashi
*Department of Applied Chemistry, Nagoya Institute of Technology, Gokiso-cho, Showa-ku, Nagoya 466-8555, Japan
Abstract
Reaction of 1-carbomethoxy-1H-azepine with N,α-diphenylnitrone afforded two stereochemical isomers in almost the same ratio. The analysis of the nmr spectra of the cycloadducts were confirmed by good coincidence of the spectra to those obtained by computer assisted line shape simulation. The analogous result was obtained in the reaction using 1-carboethoxy-1H-1,2-diazepine. The reaction is considered to proceed through concerted [4+2]-type 1,3-dipolar cycloadditions of the nitrone to 4,5-positions of the azepine or diazepine to give endo- and exo-type adducts because of the absence of stabilization effects by secondary orbital interactions in the transition states.
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■ An Enantioselective Construction of Pyrrolidones Bearing Functionalized Appendages via an Asymmetric Intramolecular Michael Reaction
Yoshiro Hirai, Takashi Terada, Hideko Katoh, Sayuri Sonohara, and Takefumi Momose*
*Faculty of Pharmaceutical Sciences, Toyama Medical and Pharmaceutical University, 2630 Sugitani, Toyama, Toyama 930-0194, Japan
Abstract
The intramolecular Michael reaction of acyclic compounds 9 and 10 to form pyrrolidones is reported. Cyclization of 9 and 10 using (R)-(+)-1-phenylethylamine as a mediator gave the pyrrolidones (+)-11 and (+)-12 in 63% and 65% enantiomeric excess, respectively. when (S)-(-)-1-phenylethylamine was used, (-)-11 and (-)-12 were obtained in similar optical yields, respectively.
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■ Gigantetrocin and Gigantriocin: Two Novel Bioactive Annonaceous Acetogenins from Goniothalamus giganteus
Xin-Ping Fang, J. Kent Rupprecht, Ahmed Alkofahi, Yu-Hua Hui, Ya-Mei Liu, David L. Smith, Karl V. Wood, and Jerry L. McLaughlin*
*Department of Medicinal Chemistry and Pharmacognosy, School of Pharmacy and Pharmacal Sciences, Purdue University, 1333 Robert E. Heine Pharmacy Building, West Lafayette IN 47907, U.S.A.
Abstract
The structural elucidations of gigantetrocin, and gigantriocin two novel bioactive monotetrahydrofuran acetogenins with vicinyl hydroxyls are presented. These compounds are significantly and selectively cytotoxic to human tumor cells in culture and toxic to brine shrimp, and they inhibit the formation of crown gall tumors on potato discs, showing good potential for in vivo antitumor activities.
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■ Calicophirins A and B, Two New Insect Growth Inhibitory Diterpenoids from a Gorgonian Coral Calicogorgia Sp.
Masamitsu Ochi,* Koji Yamada, Katsuyuki Shirasse, Hiyoshizo Kotsuki, and Kozo Shibata*
*Department of Material Science, Faculty of Science, Kochi University, 2-5-1, Akebono-cho, Kochi 780-8520, Japan
Abstract
Two new diterpenoids, calicophirins A and B, which exhibit insect growth inhibitory activity against the silkworm, Bombyx mori L., have been isolated from a gorgonian coral Calicogorgia sp. and their structure were fully characterized by extensive 2D-nmr studies.
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■ A Novel Route to 1-Azaazulenes by the Reaction of β-Amino Enones with Activated Tropones
Makoto Nitta,* Satoshi Mori, and Yukio Iino
*Department of Chemistry, School of Science and Engineering, Waseda University, 3-4-1 Okubo, Shinjuku-ku, Tokyo 169-8555, Japan
Abstract
The reactions of β-amino enones with activated tropones (2-bromo-, 2-chloro-, and 2-tosyloxytropones) underwent an enamine alkylation followed by dehydrating condensation to give 1-azaazulene derivatives in modest yields.
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■ Litophynins F, G, and H, Three New Diterpenoids from a Soft Coral Litophyton Sp.
Masamitsu Ochi,* Koji Yamada, Kensuke Futatsugi, Hiyoshizo Kotsuki, and Kozo Shibata*
*Faculty of Science, Kochi University, 2-5-1, Akebono-cho, Kochi 780-8520, Japan
Abstract
Three new diterpenoids, litophynins F (1), G (2), and H (3), have been isolated from a soft coral Litophyton sp. and their structures were determined by spectroscopic and chemical methods.
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■ Synthesis and Reactivity of 1,1-Dihydro-2-oximino-3-aryl-3H-naphtho[2,1-b]pyrans
Rajagopal Rama* and Vakipuram R. Srinivasan
*Department of Chemistry, Osmania University, Hyderabad 500 007, India
Abstract
A series of 1,1-dihydro-2-oxoimino-3-arylnaphtho[2,1-b]pyrans were synthesised in good yields by reduction of the corresponding 2-nitronaphthopyrans using Raney Nickel and hydrazine hydrate or sodium borohydride in ethanol. Further, the Beckmann rearrangement product on the oxime using phosphorous pentachloride in ether was identified as 1-cyanomethyl-2-naphthol. Whereas using sulfuric acid as the catalyst the product was characterised as 4-arylnaphth[1,2-f][1,4]oxazepine.
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■ Synthesis of Angular Benzodipyrazoles and Related Systems
Norton P. Peet* and Michael E. LeTourneau
*Merrell Dow Research Institute, 2110 East Galbraith Road, Cincinnati, Ohio 45215, U.S.A.
Abstract
A series of benzo[1,2-c:3,4-c’]dipyrazoles was prepared from cyclohexane-1,3-dione. Several related systems with different central rings were also prepared. In addition, benzo[1,2-c:4,3-c’]dipyrazoles were synthesized from 1,4-cyclohexanedione monoethylene ketal.
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■ A Regioselective Synthesis of 2-Alkylfuro[3,2-c]quinolin-4(5H)-ones
Krishna C. Majumdar* and Prabir K. Choudhury
*Department of Chemistry, University of Kalyani, Kalyani 741 235, West Bengal, India
Abstract
The title compounds (2a-h) were obtained in moderate yields by simply refluxing 1-alkyl-4-hydroxyquinolin-2(1H)-ones (1a,b) with a number of acetylenic halides in n-butanol in the presence of anhydrous potassium carbonate. Compounds (2h,i) were also obtained from 4-[2’-chloroprop-2-enyloxy][1]quinolin-2(1H)-ones (11a,b) via [3,3] sigmatropic rearrangement and cyclisation of the intermediate chloroallylic enols (13a,b) with aqueous ethanolic potassium hydroxide.
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■ Synthesis of 6,7-Disubstituted Pteridine-2,4-diones
Chiara B. Vicentini, Augusto C. Veronese, Mario Guarneri, and Paolo Giori*
*Dipartimento di Scienze Farmaceutiche, Università di Ferrara, via Fossato di Mortara 17, I-44100, Ferrara, Italy
Abstract
The reaction of pyrimido[5,4-c][1,2,5]oxadiazin-3(5H)-one (1) with carbon nucleophiles afforded pteridine-2,4-diones (3) bearing a variety of substituents unequivocally positioned in the pyrazine ring.
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■ Synthesis of the Parent Systems of Dipyrrolo[1,2-a:2’,1’-c]pyrazine and of Dipyrrolo[1,2-a:2’,1’-c]quinoxaline
Anna Berlin, Stefano Martina, Giorgio Pagani,* Gilberto Schiavon, and Gianni Zotti
*Dipartimento di Chimica Organica e Industriale, Università digli Studi di Milano, via Golgi 19, I-20133 Milano, Italy
Abstract
A synthesis of the title compounds is described starting from 2,3-dimethylpyrazine and 2,3-dimethylquinoxaline, respectively. The two pyrrole rings are formed in two subsequent steps by condensation of the methyl groups of the starting azines with the carbonyl groups of the ethyl pyruvate moiety linked to the ring nitrogen atoms. Deuterium exchange reactions of dipyrrolo [1,2-a:2’,1’-c]pyrazine are also reported.
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■ The Synthesis of a 6-Carbamoyl Substituted Carbapenem
Harold Mastalerz* and Marcel Ménard
*Bristol-Myers Squibb Pharmaceutical Group, 100 Industrial Blvd., Candiac, QC J5R 1J1, Canada
Abstract
A 6-(1-pyrrolidinylcarbonyl)substituted carbapenem was prepared. This compound has a half-life of 1.3 h (pH 7.4, 37 °C) and exhibits moderate activity against Gram-positive bacteria.
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■ A Facile Synthesis of Substituted 4-Hydroxy-2-pyridones
Kun Hoe Chung, Kwang Yun Cho, Yasuko Asami, Nobutaka Takahashi,* and Shigeo Yoshida
*Department of Agricultural Chemistry, Faculty of Agricultural and Life Sciences, University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-0032, Japan
Abstract
Substituted 4-hydroxy-2-pyridones (1a-1d) were easily synthesized from ethyl acetoacetate in good yields via C-alkylation, enamine formation, N-acylation, intramolecular cyclization, and debenzylation.
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■ Synthesis of Thieno[3,2-f]morphan, Thieno[4,3-f]morphan and 3-Thiamorphinan Derivatives
Masatoshi Ban, Yutaka Baba, Kenji Miura, Yasuaki Kondo, and Mikio Hori*
*Department of Pharmacognosy, Gifu College of Pharmacy, 6-1 Mitahora-higashi 5-chome, Gifu 502-8585, Japan
Abstract
Thieno[3,2-f]morphans (4-7), (27) and (28) were prepared by cyclization of 2-thenyl-4-hydroxypiperidines (3) or 2-thenyltetrahydropyridine (26) with hydrobromic acid. Thieno[4,3-f]morphans (37) and (38) and 3-thiamorphinan (47) were similarly prepared. Some kinds of N-substituents were introduced to the thienomorphans (5-7), (29) and (39) and a 3-thiamorphinan (48). Analgesic activities of the N-substituted compounds were investigated.
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■ Heterocyclic Aromaticity
Alan R. Katritzky,* Mati Karelson, and Nageshwar Malhotra
*Center for Heterocyclic Compounds, Department of Chemistry, University of Florida, P. O. Box 117200, Gainesville, FL 32611-7200, U.S.A.
Abstract
The concept of aromaticity for heterocyclic compounds is summarized. The different methods available for calculating aromaticity are discussed. Overall conclusion are presented together with the outlook for further work.