Regular Issue

Vol. 32, No. 1, 1991

15 data found. 1 - 15 listed
Communication | Regular issue | Vol 32, No. 1, 1991, pp. 1 - 6
Published online:
DOI: 10.3987/COM-90-5495
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


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.

PDF (125KB)
Communication | Regular issue | Vol 32, No. 1, 1991, pp. 7 - 10
Published online:
DOI: 10.3987/COM-90-5604
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


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.

PDF (115KB)
Communication | Regular issue | Vol 32, No. 1, 1991, pp. 11 - 17
Published online:
DOI: 10.3987/COM-90-5610
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.


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.

PDF (195KB)
Communication | Regular issue | Vol 32, No. 1, 1991, pp. 19 - 21
Published online:
DOI: 10.3987/COM-90-5624
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


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.

PDF (76KB)
Communication | Regular issue | Vol 32, No. 1, 1991, pp. 23 - 28
Published online:
DOI: 10.3987/COM-90-5643
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


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.

PDF (130KB)
Communication | Regular issue | Vol 32, No. 1, 1991, pp. 29 - 32
Published online:
DOI: 10.3987/COM-90-5649
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


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.

PDF (104KB)
Paper | Regular issue | Vol 32, No. 1, 1991, pp. 33 - 39
Published online:
DOI: 10.3987/COM-89-5029
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


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.

PDF (149KB)
Paper | Regular issue | Vol 32, No. 1, 1991, pp. 41 - 72
Published online:
DOI: 10.3987/COM-90-5594
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.


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.

PDF (722KB)
Paper | Regular issue | Vol 32, No. 1, 1991, pp. 73 - 78
Published online:
DOI: 10.3987/COM-90-5599
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


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.

PDF (171KB)
Paper | Regular issue | Vol 32, No. 1, 1991, pp. 79 - 84
Published online:
DOI: 10.3987/COM-90-5617
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


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.

PDF (153KB)
Paper | Regular issue | Vol 32, No. 1, 1991, pp. 85 - 92
Published online:
DOI: 10.3987/COM-90-5619
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


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.

PDF (255KB)
Paper | Regular issue | Vol 32, No. 1, 1991, pp. 93 - 98
Published online:
DOI: 10.3987/COM-90-5621
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


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.

PDF (151KB)
Paper | Regular issue | Vol 32, No. 1, 1991, pp. 99 - 105
Published online:
DOI: 10.3987/COM-90-5631
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


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.

PDF (195KB)
Paper | Regular issue | Vol 32, No. 1, 1991, pp. 107 - 126
Published online:
DOI: 10.3987/COM-90-5641
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


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.

PDF (559KB)
Review | Regular issue | Vol 32, No. 1, 1991, pp. 127 - 161
Published online:
DOI: 10.3987/REV-90-420
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.


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.

PDF (620KB)
15 data found. 1 - 15 listed