Regular Issue

Vol. 45, No. 2, 1997

17 data found. 1 - 17 listed
Communication | Regular issue | Vol 45, No. 2, 1997, pp.231-234
Published online:
DOI: 10.3987/COM-96-7638
Studies Directed toward the Synthesis of Martinellines : One Pot Synthesis of Pyrroloquinolone Ring System

Mukund K. Gurjar,* Shashwati Pal, and A. V. Rama Rao

*Indian Institute of Chemical Technology, Hyderabad 500 007, India

Abstract

The Pd-catalysed coupling between aryl iodides and 3-carbethoxy-4,5-dihydroppyrroles has been described. With ortho-iodoanilines, tandem cyclisation leading to pyrroloquinolones present in martinellines, was observed.

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Communication | Regular issue | Vol 45, No. 2, 1997, pp.235-240
Published online:
DOI: 10.3987/COM-96-7682
2-Bromo-2-nitropropane/Zn Promoted Reductive Cyclizations of Ortho-substituted Nitroarenes toward 2,1-Benzisoxazole Derivatives

Byeong Hyo Kim,* Young Moo Jun, Tae Kyu Kim, Yoon Seok Lee, Woonphil Baik, and Byung Min Lee

*Department of Chemistry, Research Institute of Basic Science, Kwangwoon University, 447-1, Wolgye-Dong Nowon-ku, Seoul, 139-701, Korea

Abstract

Under the mild conditions, reductive cyclizations of 2-nitrobenzaldehydes or 2’-nitroacetophenone towards 2,1-benzisoxazoles were accomplished in the presence of 2-bromo-2-nitropropane/Zn in methanolic solution. The synthetic utility and the role of 2-bromo-2-nitropropane were investigated.

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Paper | Regular issue | Vol 45, No. 2, 1997, pp.241-253
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DOI: 10.3987/COM-96-7608
Synthesis of Some Conformationally-constrained Glutamate Mimics of N-{5-[2-Amino-3,4-dihydro-4-oxo-5,6,7,8-tetrahydropyrido[2,3-d]pyrimidine-6-yl)ethyl]thien-2-ylcarbonyl]-L-glutamic Acid (LY254155)

Edward C. Taylor* and Baihua Hu

*Department of Chemistry, Princeton University, Princeton, New Jersey 08544, U.S.A.

Abstract

Several new analogues of the active antitumor agent N-{5-[2-(2-amino-3,4-dihydro-4-oxo-5,6,7,8-tetrahydropyrido[2,3-d]pyrimidin-6-yl)ethyl]thien-2-ylcarbonyl}-L-glutamic acid (LY254155) have been prepared in which the glutamate moiety has been replaced with conformationally-constrained azetidine and cyclopropane mimics. None of these new analogues exhibited significant cell growth inhibitory activity.

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Paper | Regular issue | Vol 45, No. 2, 1997, pp.255-264
Published online:
DOI: 10.3987/COM-96-7613
Thienopyridone Antibacterials. Part I. A Synthesis of Some 7-Alkyl-2-chloro-1,4-dihydro-1-oxothieno[2,3-b]pyridine-5-carboxylic Acids

Mustafa M. El-Abadelah,* Salim S. Sabri, and Haneen A. Al-Ashqar

*Chemistry Department, Faculty of Science, University of Jordan, Amman 11942, Jordan

Abstract

A selected set of 7-alkyl-4-oxothieno[2,3-b]pyridine-5-carboxylic acids (7) and their methyl esters (6) were prepared by cyclization of the respective 3-N-alkylamino-2-(2,5-dichloro-3-thienoyl)acrylates (5) which, in turn, are accessible via methyl 3-(2,5-dichlorothien-3-yl)-3-oxopropanoate (3). Of the present series, the N-cyclopropyl derivative (7b) exhibited the highest potency against Escherichia coli (MIc = 0.5 μg/ml).

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Paper | Regular issue | Vol 45, No. 2, 1997, pp.265-270
Published online:
DOI: 10.3987/COM-96-7626
Synthesis of Dioxolanylclavam from Tartaric Acid

Oliver Neuß, Bartlomiej Furman, Zbigniew Kaluza, and Marek Chmielewski*

*Institute of Organic Chemistry, Polish Academy of Sciences, ul. Kasprzaka 44/52, P.O. Box 58, 01-244 Warsaw, Poland

Abstract

[2+2] Cycloaddition of chlorosulfonyl isocyanate ot the 3-O-vinyl ether (8) derived from tartaric acid provides 4-alkoxy-azetidin-2-one (9) with 91.0% d.e.. Intramolecular N-alkylation afforded clavam (11) which corresponds to clavulanic acid missing the C-3 carboxylic function.

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Paper | Regular issue | Vol 45, No. 2, 1997, pp.271-276
Published online:
DOI: 10.3987/COM-96-7634
Synthesis of 2,3,4,6-Tetra-substituted Pyridines from N-Silyl-1-aza-allyl Anions and 1,3-Diphenyl-2-propen-1-one

Takeo Konakahara,* Marhaba Hojahmat, and Kenji Sujimoto

*Department of Industrial Chemistry, Faculty of Science and Technology, Science University of Tokyo, 2641 Yamazaki, Noda, Chiba 278-8510, Japan

Abstract

The reaction of N-silyl-1-aza-allyl anions (3) with 1,3-diphenyl-2-propen-1-one (4) is described. The anions (3a-f), which were prepared from an α-silyl carbanion of 3-methyl-5-trimethylsilylmethylisoxazole (1a) [or 2-trimethylsilylmethylpyridine (1b)] and p-substituted benzonitriles (2a-e, R1 = H, p-Me, p-OMe, p-Cl, p-CF3), reacted with a slightly excess amount of 1,3-diphenyl-2-propen-1-one (4) to afford 2,3,4,6-tetra-substituted pyridine derivatives (5a-f) in good yields. But the analogous reaction of the anion (3e) with cinnamaldehyde or methyl vinyl ketone did not give the corresponding pyridines.

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Paper | Regular issue | Vol 45, No. 2, 1997, pp.277-286
Published online:
DOI: 10.3987/COM-96-7650
Addition of 2-Trimethylsilyloxyfuran to Catalytically Generated N-Methyleneamine Equivalents: Synthesis of 5-Aminomethyl-2,5-dihydrofuran-2-ones

Hyun-Joon Ha,* Kyung-Ho Kang, Young-Gil Ahn, and Seung-Jun Oh

*Department of Chemistry, Hankuk University of Foreign Studies, Yongin, Kyunggi-Do, 449-791, Korea

Abstract

Catalytically generated N-methyleneamine equivalents from N-methoxymethylanilines, 1,3,5-triphenyl- and 1,3,5-tribenzylhexahydro-1,3,5-triazines in the presence of Lewis acid reacted with 2-trimethylsilyloxyfuran to give 5-aminomethyl-2,5-dihydrofuran-2-ones in high yield.

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Paper | Regular issue | Vol 45, No. 2, 1997, pp.287-298
Published online:
DOI: 10.3987/COM-96-7651
Conformational Analysis of Tetrahydrofurofuran Lignans: Sesamolin

Gerda Lutz, Otmar Hofer,* Günter Brader, and Christoph Kratky

*Institute of Organic Chemistry, University of Vienna, Währingerstrasse 38, A-1090 Vienna, Austria

Abstract

The stereochemisty of sesamolin (1), an aryl-aryloxy-tetrahydrofurofuran derivative comprising a main component of the lignans isolated from Sesamum indicum, was investigated. the favoured conformation was determined using several methods of conformational analysis: nuclear Overhauser effect (NOE), lanthanide induced shifts (1H-LIS), molecular mechanics (force-field) calculations (FF), and X-ray crystal structure determination. The conformation was found to be deviate from the more common analoguous diaryltetrahydrofurofuran derivatives. The reason is the anomeric effect of the cyclic acetal favouring a pseudo-axial position of the aryloxy substituent.

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Paper | Regular issue | Vol 45, No. 2, 1997, pp.299-307
Published online:
DOI: 10.3987/COM-96-7652
New Linear Pyranoxanthones from Calophyllum apetalum

Munekazu Iinuma,* Tetsuro Ito, Hideki Tosa, Toshiyuki Tanaka, Ryoko Miyake, and Veliah Chelladurai

*Departmeny of Pharmacognosy, Gifu Pharmaceutical University, 6-1 Mitahora-higashi 5-chome, Gifu 502-8585, Japan

Abstract

The invesitgation of chemical constituents in stem bark and root of Calophyllum apetalum (Guttiferae) led to isolate sixteen xanthones and two coumarin derivatives. Among them, two linear pyranoxanthones [caloxanthones I (1) and J (2)] from the stem bark, and two xanthones [caloxanthone K (10) and 1,3,6,8-trihydroxy-2-methoxyxanthone (12)] from the root were new ones. The respective structures were determined by the spectral analysis.

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Paper | Regular issue | Vol 45, No. 2, 1997, pp.309-314
Published online:
DOI: 10.3987/COM-96-7657
Alkylation of Pyrazolones via the Mitsunobu Reaction

Wolfgang Holzer,* Brigitte Plagens, and Karin Lorenz

*Institute of Pharmaceutical Chemistry, University of Vienna, Währinger Strasse 10, A-1090 Vienna, Austria

Abstract

The reaction of 3-methyl-1-phenyl-2-pyrazolin-5-one and 4-acyl derivatives thereof (R4 = COPh, 2-thienoyl, COCH2CH2Ph, COCH=CHPh) with various alcohols under ’Mitsunobu’-conditions was studied. In many cases selective O-alkylation could be achieved.

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Paper | Regular issue | Vol 45, No. 2, 1997, pp.315-322
Published online:
DOI: 10.3987/COM-96-7664
Synthesis and Conformational Analysis cis-3a-(o-Nitrophenyl)octahydroindol-4-ol Derivatives

Josep Bonjoch,* Daniel Solé, and Xavier Cuesta

*Laboratory of Organic Chemistry, Faculty of Pharmacy, University of Barcelona, Av. de Joan XXIII, s/n, 08028 Barcelona, Spain

Abstract

The preparation of 1-methyl-3a-(o-nitrophenyl)octahydroindol-4-ol derivatives from 2-allyl-2-(o-nitrophenyl)-1,3-cyclohexanedione (1) and the preferred conformation of the azabicyclic ring system of these compounds are reported.

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Paper | Regular issue | Vol 45, No. 2, 1997, pp.323-330
Published online:
DOI: 10.3987/COM-96-7673
Preparation of Cycloalkano[c]pyridazinoens and Cycloalkane-condensed Pyrrolo[1,2-a]imidazolone, -pyrimidinone and -[1,3]diazepinone Stereoisomers

Ferenc Csende, Gábor Bernáth,* Zsolt Böcskei, Pál Sohár, and Géza Stájer

*Institute of Pharmaceutical Chemistry, Albert Szent-Györgyi Medical University, H-6701 Szeged, Eötv¨øs u.6., Hungary

Abstract

From the 2-ethoxycarbonylmethyl-1-cycloalkanones (1a-c) with hydrazine, the cyclopenta- (2a), cyclohexa-(2b) and cyclohepta[c]pyridazinones (2c) were prepared. 2a-c were transformed to the corresponding dehydro derivatives (3a-c) by means of recently-developed smooth oxidation method with CuCl2 in acetonitrile. Compounds (1) reacted with α,ω-alkylenediamines to furnish saturated cycloalkano[b]pyrrolo[1,2-a]diazinones (4a-f). The Structures of 4a-f were determined by 1H- and 13C-NMR methods, including DNOE, DEPT and 2D-HSC measurements, and for 4a also by X-ray analysis. The rings of the 2-perhydroindolone and its homologues are cis-fused, while the NH group of the heterocycle containing two N atoms and the annelational hydrogen are cis in all compounds prepared.

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Paper | Regular issue | Vol 45, No. 2, 1997, pp.331-338
Published online:
DOI: 10.3987/COM-96-7679
Brewers' Yeast-mediated Synthesis of (1S,2S)-1-(2-Thienyl)-1,2-propanediol and a Study on the Lipase-catalyzed Regioselective Introduction of Acyl Protective Group to the Diol Moiety

Naoki Mochizuki, Takeshi Sugai, Hiromichi Ohta, Tsutomu Yokomatsu, and Shiroshi Shibuya*

*School of Pharmacy, Tokyo University of Pharmacy and Life Science, 1432-1 Horinouchi, Hachioji, Tokyo 192-0392, Japan

Abstract

Reductive homologation of thiophenecarboxyaldehyde mediated by brewers’ yeast and subsequent recrystallization provided (1S,2S)-1-(2-thienyl)-1,2-propanediol in 29% yield. A Pseudomonas lipase-catalyzed acetylation preferentially occurred on the hydroxyl group at C-1 position of the diol.

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Paper | Regular issue | Vol 45, No. 2, 1997, pp.339-346
Published online:
DOI: 10.3987/COM-96-7680
A Simple and Efficient Synthetic Method for Fluorine-containing Benzo[h]qunolines

Etsuji Okada,* Hiroshi Tone, Norikado Tsukushi, Yoshihiro Otsuki, Hiroshi Takeuchi, and Masaru Hojo

*Department of Chemical Science and Engineerring, Faculty of Engineering, Kobe University, Rokkodai-cho, Nada-ku, Kobe 657-8501, Japan

Abstract

N-Propargyl-2,4-bis(trifluoroacetyl)-1-naphthylamine (2), prepared from N,N-dimethyl-2,4-bis(trifluoroactyl)-1-naphthylamine (1) and propargylamine, undergoes ring forming reaction with amines, thiolates and alcoholates under mild conditions to afford the corresponding 6-trifluoroacetyl-4-trifluoromethylbenzo[h]quinolines (3) in excellent yields.

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Paper | Regular issue | Vol 45, No. 2, 1997, pp.347-359
Published online:
DOI: 10.3987/COM-96-7687
Manganese(III) Acetate Initiated Oxidative Free Radical Reaction between Benzoylindoles and Dimethyl Malonate

Sheouw-Fong Wang and Che-Ping Chuang*

*Department of Chemistry, Natioanl Cheng Kung University, Tainan, 70101, Taiwan, R.O.C.

Abstract

A free radical reaction between benzoylindoles and dimethyl malonate initiated by manganese (III) acetate is described. this free radical reaction provides a new method for the synthesis of indolo[1,2-b]isoquinolines and benzo[b]carbazoles. With meta substituent on benzoyl group, this reaction shows unusual high regioselectivity.

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Note | Regular issue | Vol 45, No. 2, 1997, pp.361-366
Published online:
DOI: 10.3987/COM-96-7675
Lactone Formation as an Aid in the NMR Characterization of Two 3-(1'-Hydroxyethyl)indolo[2,3-a]qunolizidine-1-carboxylates: Intermediates for the Stereoselective Synthesis of Tacamine-Type Indole Alkaloids

Mauri Lounasmaa,* Kimmo Karinen, David Din Belle, and Arto Tolvanen

*Laboratory for Organic and Bioorganic Chemistry, Technical University of Helsinki, P.O. Box 6100, FIN-02150 HUT Espoo, Finland

Abstract

NMR spectral characterization of methyl 3-(1’-hydroxyethyl)-1,2,3,4,6,7,12,12b-octahydroindolo[2,3-a]quinolizine-1-carboxylates (3) and (4) is described. The configuration at the hydroxyethyl side chain was confirmed by NOE difference spectroscopy performed on 3-(1’-hydroxyethyl)-1,2,3,4,6,7,12,12b-octahydroindolo[2,3-a]quinolizine-1-carboxylic acid lactones (5) and (6) obtained by epimerization of 3 and 4. Base treatment of 3 and 4, followed by esterification, led to methyl 3-(1’-hydroxyethyl)-1,2,3,4,6,7,12,12b-octahydroindolo[2,3-a]quinolizine-1-carboxylates (7) and (8), which are new intermediates for the preparation of tacamine-type indole alkaloids.

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Review | Regular issue | Vol 45, No. 2, 1997, pp.367-383
Published online:
DOI: 10.3987/REV-96-487
Asymmetric Total Synthesis of Antitumor Styryl Lactones and Related Natural Products

Zhi-Cai Yang and Wei-Shan Zhou *

*Shanghai Institute of Organic Chemistry, Chinese Academy of Science, 354 Finglin Lu, Shanghai 200032, China

Abstract

Total synthesis of antitumor styryl lactones based on Sharpless asymmetric dihydroxylation and asymmetric epoxidation starting from methyl cinnamate and cinnamyl alcohol, respectively, was described. Synthesis of the natural asperlin and its related compound by peculiar kinetic resolution was also described.

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17 data found. 1 - 17 listed