Regular Issue

Vol. 29, No. 1, 1989

25 data found. 1 - 25 listed
Communication | Regular issue | Vol 29, No. 1, 1989, pp. 1 - 4
Published online:
DOI: 10.3987/COM-88-4626
Reaction of Glycosylisothiocyanates with 2-Chloroethylamine

M. Avalos Gonzárez, R. Babiano Caballero, P. Cintas Moreno, J. Fuentes Mota, J. L. Jiménez Requejo, and J. C. Palacios Albarrán*

*Department of Organic Chemistry, Facultad de Veterinard, University of Extremadura, 06071-Badajoz, Spain

Abstract

The products formed in the reaction of per-O-acyl-glycosylisothiocyanatea withÅ@ω-haloalkylamines are shown to be glycosylamino- and N,N’-bis-glycosyl-heterocycles.

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Communication | Regular issue | Vol 29, No. 1, 1989, pp. 5 - 9
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DOI: 10.3987/COM-88-4719
Ring Conversion of 2-Amino-4,5-dihydro-3-furancarbonitriles Catalyzed by Halide Ions

Kenji Yamagata, Hiroshi Maruoka, Yoshichika Hashimoto, and Motoyoshi Yamazaki*

*Faculty of Pharmaceutical Sciences, Fukuoka University, 8-19-1 Nanakuma, Jonan-ku, Fukuoka 814-0180, Japan

Abstract

The reaction of 2-amino-4,5-dihydro-3-furancarbonitrile (1a) with methylamine hydrochloride in dimethylformamide gave 1-cyano-N-methylcyclopropanecarboxamide (2). Similarly. 2-amino-4,5-dihydro-4-phenyl(and 5-phenyl)-3-furancarbonitriles [(1b) and (1c)] provided (E)-1-cyano-N-methyl-2-phenylcyclopropanecarboxamide (3). Compound 1b reacted with sodium iodide to give (E)-1-cyano-2-phenylcyclopropanecarboxamide (6). On the other hand, 2-benzamido-4,5-dihydro-3-furancarbonitrile (7a) reacted with sodium iodide to furnish 1-benzoyl-2-oxo-3-pyrrolidinecarbonitrile (8).

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Communication | Regular issue | Vol 29, No. 1, 1989, pp. 11 - 20
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DOI: 10.3987/COM-88-4763
Regioselectivity in the Diels-Alder Reactions of 2-Vinylindoles and Pyrano[3,4-b]indol-3-ones with CC-Dienophiles

Ulf Pindur,* Manfred Eitel, and Erfanian Abdoust-Houshang

*Department of Chemistry and Pharmacy, Institute of Pharmacy, University of Mainz, Saarstrasse 21, D-55122 Mainz, Germany

Abstract

Diels-Alder reactions of 2-vinylindoles 1 and methylated pyrano[5,4-b]indol-3-ones 6 with acceptor-substituted CC-dienophiles (e.g.propynoates, ethyl phenylpropynoate, acrylonitrile, α-chlnroacrylonitrile, methyl acrylate, 1-penten-3-one) proceed with poor to high regioselectivities to furnish functionalized carbazole derivatives. MNDO calculations have been carried out for the 2-vinylindole and pyrano[3,4-b] indol-3-one parent compounds and, in most cases, qualitative FMO analyses correctly predict the major products. The regiochemistries of the products from the reactions of the pyrano[3,4-b]indol-3-ones 6 with ethyl phenylpropynoate can be predicted by the simple charge controlled orientation in the transition states.

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Communication | Regular issue | Vol 29, No. 1, 1989, pp. 21 - 24
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DOI: 10.3987/COM-88-4764
Formation of Novel 1:3 Adduct in the High Pressure Reaction of 2(1H)-Pyridones with Dimethyl Acetylenedicarboxylate: An X-Ray Crystal Structure Determination

Kiyoshi Matsumoto,* Kensaku Hamada, Takane Uchida, and Hiroshi Yoshida

*College of Liberal Arts and Science, Kyoto University, Yoshida, Sakyou-ku, Kyoto 606-8501, Japan

Abstract

The structure of the 1:3 adduct from 1-(5’,5’-dimethylcyclohex-2’-en-1’-on-3’-yl)-2(1H)-pyridone and dimethyl acetylenedicarboxylate was determined, possible mechanism for the reaction being presented.

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Communication | Regular issue | Vol 29, No. 1, 1989, pp. 25 - 28
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DOI: 10.3987/COM-88-4770
Synthesis of 2’,3’-Dideoxy-3’-methylidenethymidine and 2’,3’-Didehydro-2’,3’-dideoxy-3’-methylthymidine: Deoxygenation of the Allylic Alchol System in 3’-Deoxy-3’-methyodene-5-methyluridine

Akira Matsuda,* Hitomi Okajima, and Tohru Ueda

*Faculty of Pharmaceutical Sciences, Hokkaido University, Kita 12 Nishi 6, Kita-ku, Sapporo, Hokkaido 060-0812, Japan

Abstract

Synthesis of 2’,3’-dideoxy-3’-methylidenethymidine (10) was accomplished by palladium calalyzed deoxygenation of 3’-deoxy-3’-methylidene-5-methyluridine derivative (7). 2’,3’-Didehydro-2’,3’-dideoxy-3’-methylthymidine (11) was synthesized by radical deoxygenation of 3’-deoxy-3’-methylidene-5-methyluridine derivatives.

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Communication | Regular issue | Vol 29, No. 1, 1989, pp. 29 - 34
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DOI: 10.3987/COM-88-4772
Asymmetric Electrophilic α-Amidoalkylation 6: Syntheses of Tetrahydroisoquinolines of High Enantiomeric Purity

Klaus Th. Wanner* and Ilona Praschak

*Institut für Pharmazie, Universität München, Sophienstraße 10, D-80333 München, Germany

Abstract

Syntheses of 1-substituted tetrahydroisoquinolines of high enantiomeric purity are described. As key step a diastereoselective trapping reaction of a chiral acyliminium ion with silyl enol ethers is involved. The starting acyliminium ion can be prepared by hydride abstraction with triphenylcarbonium tetrafluoroborate.

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Communication | Regular issue | Vol 29, No. 1, 1989, pp. 35 - 38
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DOI: 10.3987/COM-88-4774
(4+2)type Cycloaddition of Chromones with α,β-Unsaturated Ketones Mediated by t-Butyldimethylsilyl Triflate: One-pot Preparation of Xanthone Derivatives

Yong-gyun Lee, Hideharu Iwasaki, Yosuke Yamamoto, Katsuo Ohtaka, and Kin-ya Akiba*

*Department of Chemistry, Faculty of Science, Hiroshima University, 1-3-1 Kagamiyama, Higashi-Hiroshima, Hiroshima 739-8526, Japan

Abstract

4-t-Butyldimethylsiloxy-1-benzopyrylium salt (2a,b) reacted with various α,β-unsaturated ketones (3a-g) in the Presence of t-BuMe2SiOTf and 2,6-lutidine to afford the corresponding (4+2) type cycloadducts (4a-i) in high yield. The ring fusion of the adduct was determined to be cis geometry on the basis of the 1H nmr spectral features.

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Communication | Regular issue | Vol 29, No. 1, 1989, pp. 39 - 41
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DOI: 10.3987/COM-88-4780
Litophytolides A and B, Two New Lipid Metabolites of a Soft Coral Litophyton sp.

Masamitsu Ochi,* Kensuke Futatsugi, Yasuhiro Kume, Hiyosizo Kotsuki, Kazuhuko Asao, and Kozo Shibata*

*Department of Material Science, Faculty of Science, Kochi University, 2-5-1, Akebono-cho, Kochi 780-8520, Japan

Abstract

The structures of litophytolides A and B, two new branchedchain lipids containing a γ-lactone ring isolated from a soft coral Litophyton sp., have been established as 1 and 2 on the basis of spectral and chemical evidence.

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Paper | Regular issue | Vol 29, No. 1, 1989, pp. 43 - 49
Published online:
DOI: 10.3987/COM-86-3641
The Chemistry of the 6β-Diacylaminopenicillins

Ronald G. Micetich, Rajeshwar Singh, Chen C. Shaw, Samarandra N. Maiti, Maya P. Singh, and Paul Spevak

*SynPhar Laboratories Inc., 4290-91A Street, Edmonton, Alberta, T6E 5V2, Canada

Abstract

A comparison of the chemical reactions of 6β-amidopenicillins, 6β-phthalimidopenicillins and 6β-diacylaminopenicillins with trimethyl phosphite and with benzyl and heteroaryl thiols is reported. The reaction of the unsym-azetidinone disulfides, obtained from the reaction of penicillin sulfoxides with 2-mercaptobenzothiazole, with halogenating agents is also discussed.

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Paper | Regular issue | Vol 29, No. 1, 1989, pp. 51 - 56
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DOI: 10.3987/COM-88-4591
A New Synthetic Route to Heterocyclic Quinones

Abdulla J. Hamdan and Harold W. Moore

*Department of Chemistry, University of California, Irvine, Irvine, California 92697, U.S.A.

Abstract

The synthesis of a variety of heterocyclic quinones is described. This involves a series of unusual transformations of azidoquinones having an active methylene group in conjugation with the azide moiety. Generation of the conjugate base induces nitrogen loss and subsequent heterocyclic ring formation.

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Paper | Regular issue | Vol 29, No. 1, 1989, pp. 57 - 65
Published online:
DOI: 10.3987/COM-88-4601
Preparation of New Benzimidazole Derivatives from N-[(Methylthio)thiocarbonylmethyl]azinium Salts

An M. Cuadro, Julio Alvarez-Builla*, and Juan J. Vaquero

*Departamento de Química Orgánica, Universidad de Alcalá de Henares, 28871 Alcalá de Henares (Madrid), Spain

Abstract

A series of new N-[(methylthio)thiocarbonylmethyl] azinium salts has been synthesized by reaction of carbon disulphide and methyl iodide with the corresponding phenacylazinium salt in a two-phase system followed by acid treatment of the ylide thus obtained. Condensation of dithioster derivatives with o-phenylenediamines gave N-(benzimidazolylmethyl) azinium salts in good yields.

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Paper | Regular issue | Vol 29, No. 1, 1989, pp. 67 - 77
Published online:
DOI: 10.3987/COM-88-4622
A Novel Mehtod for the Synthesis of 2-Haloalkyl-3(2H)-pyridazinones by ON-Alkyl Rearrangement

Péter Mátyus,* Nándor Makk, Endre Kasztreiner, and Gyula Jerkovich

*Institute for Drug Research Ltd., H-1325 Budapest, POB 82, Hungary

Abstract

The reaction of (6-substituted 3-pyridazinyloxy)alkanols 2a-d, 3a-d and 14a-c with thionyl chloride is described. The 2-chloroalkylpyridazinones 5b-d, 6b-d and 15a-c were formed from 2b-d, 3b-d and 14a-c, respectively, while the 3-chloroalkoxypyridazines, 7a and 8a were isolated from the reaction of 2a and 3a, respectively. It was shown by chemical and spectroscopic evidences that the rearrangement reaction followed an intramolecular process through bicyclic intermediates.

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Paper | Regular issue | Vol 29, No. 1, 1989, pp. 79 - 86
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DOI: 10.3987/COM-88-4662
High-Pressure Diels-Alder Reactions of 1-Methoxycarbonyl-3-Methylthio- and -3-phenylthiopyrrole. An efficient Entry to 7-Azabicyclo[2.2.1]heptanes

Jan Keijsers, Benno Hams, Chris Kruse,* and Hans Scheeren*

*Department of Chemistry, Duphar Research Laboratories, PO Box 2, 1380 AA Weesp, The Netherlands

Abstract

The high pressure Diels-Alder reaction of new 3-thiosubstituted N-carbonylpyrrole derivatives 5 with electron-poor akenes afforded 2-thiosubstituted 7-azabicyclo[2.2.1]hept-2-enes 9, 10 and 11 regiospecifically in high over-all yields.

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Paper | Regular issue | Vol 29, No. 1, 1989, pp. 87 - 96
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DOI: 10.3987/COM-88-4683
Tetranortriterpemoids from Azadirachta Indica A, Juss (Meliaceae)

Salimuzzaman Siddiqui,* Bina Shaheen Siddiqui, Tariq Mahmood, and Shaheen Faizi

*H. E. J. Postgraduate Institute of Chemistry, University of Karachi, Karachi-75270, Pakistan

Abstract

Nimbocinolide, a new tetranortriterpenoid has been isolated from the acidic fraction of fresh, undried leaves of A.indica (neem) and its structure was established as 21, ,23-epoxy-1,14,20-apoeul (apotirucalla)-trien-3,21-dione-7α,11α,12α,23x-tetraol-11-(2’-hydroxy-2’-methyl) propio-nate-7-acetate (I), through chemical and spectral studies.

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Paper | Regular issue | Vol 29, No. 1, 1989, pp. 97 - 102
Published online:
DOI: 10.3987/COM-88-4686
Synthesis of 4-Unsubstituted Isothiazoles

Francesco Lucchesini, Nevio Picci, Marco Pocci, Angela De Munno,* and Vincenzo Bertini

*Dipartimento di Chimica e Chimica Industriale, Università di Pisa, Via Risorgnimento 35, I-56126 Pisa, Italy

Abstract

A new method for the synthesis of 4-unsubstituted isothiazoles starting from α-acetylenic aldehydes or ketones, hydroxylamine-O-sulphonic acid and sodium hydrosulfide in buffered aqueous solution by one-pot procedure, is described.

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Paper | Regular issue | Vol 29, No. 1, 1989, pp. 103 - 114
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DOI: 10.3987/COM-88-4697
Flash-Vacuum Pyrolysis of 1,2,4-Triazolides: A New Synthesis of Functionalized Oxazoles

André Maquestiau, Robert Flammang, and Fouad-Bachir Ben Adbelouahab

*Organic Chemistry Labratory, State University of Mons, B-7000 Mons, Belgium

Abstract

Tandem mass spectrometry (MS/NS) has been applied. to investigate the behaviour of 1,2,4-triazolides upon flash-vacuum pyrolysis (FVP) conditions. Monosubstituted (position 5) oxazoles (loss of nitrogen) and in some cases oxygenated cumulenes (loss of 1,2,4-triazole) are the most important pyrolysis products. Pyrolysis at a preparative scale indicates moreover the interest of the technique as the synthetized oxazoles were usually unknown or very difficult to prepare owing the conventional procedures.

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Paper | Regular issue | Vol 29, No. 1, 1989, pp. 115 - 121
Published online:
DOI: 10.3987/COM-88-4721
Photosensitized Dehydrogenation of Flavanones to Flavones Using 2,4,6-Triphenylpyrylium Tetrafluoroborate (TPT)

María J. Climent, Hermenegildo García, Sara Iborra, Miguel A. Miranda,* and Jamie Primo

*Departamento de Química Oránica, Facultad de Farmacia, Av. Blasco Ibañez 13, 46010 Valencia, Spain

Abstract

Irradiation of flavanones 1a-c,e using TPT as photosensitizer leads to the corresponding flavones 2a-c,e in yields ranging between 50 and 69%. 4-Nitroflavanone (1d) remains unchanged under the same conditions. These results are consistent. with a single electron-transfer (SET) occurring from the flavanone B ring to the excited pyrylium salt to give the radical cation intermediate 3.

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Paper | Regular issue | Vol 29, No. 1, 1989, pp. 123 - 131
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DOI: 10.3987/COM-88-4728
Alkylation and Arylation of Pyrazines by Organotin Compounds

Tokuhiro Watanabe, Kazuhiro Hayashi, Jun Sakurada, Michiyo Ohki, Noriko Takamatsu, Harumi Hirohata, Keiko Takeuchi, Kayo Yuasa, and Akihiro Ohta*

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

Abstract

The palladium-catalyzed cross-coupling reactions of chloropyrazines and tetrabutyltin gave butylpyrazines in good yields. By reactions of chloropyrazines with organotin compounds prepared in situ from the Grignard reagents, alkyl and aryl groups were satisfactorily introduced into the pyrazine ring.

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Paper | Regular issue | Vol 29, No. 1, 1989, pp. 133 - 140
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DOI: 10.3987/COM-88-4736
Synthesis of New Racemic Bicyclic γ- and δ-Lactams Based on Two-fold Intramolecular Cyclization

Eddie ViPing Tao,* John Brennan, Kohn Keith Swartzendruber, and Jack Billie Deeter

*Lilly Reserach Laboratories, Lilly Corporate Center, Eli Lilly & Company, Indianapolis, IN 46285-4813, U.S.A.

Abstract

Syntheses of new raccmic γ - and δ -lactams have been achicved via a novel two-fold intramolceular cyclization.

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Paper | Regular issue | Vol 29, No. 1, 1989, pp. 141 - 153
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DOI: 10.3987/COM-88-4739
Annelation of Quinoxaline by Sulfur Stabilized Carbanions

Jean-Michel Vierfond, Lucien Legendre, Jacqueline Mahuteau, and Marcel Miocque*

*Faculté de Pharmacie, UA 496 CNRS, 5 rue J.B. Clément, 92296 Châtenay-Malabry Cedex, France

Abstract

Thieno[3,4-b]quinoxaline derivatives were prepared by nucleophilic addition of carbanions of sulfones, sulfoxides and sulfides on quinoxaline. The use of dissymmetric sulfones or sulfoxides gave diastereoisomers which mre isolated and characterized.

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Paper | Regular issue | Vol 29, No. 1, 1989, pp. 155 - 164
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DOI: 10.3987/COM-88-4740
Witting Reactions of 1-Alkoxycarbonyl-2-hydroxypyrrolidines and -piperidines: Syntheses of (±)-Hygrine and (±)-2-Epilasubine II

Tatsuo Nagasaka,* Hiroto Yamamoto, Hideki Hayashi, Mariko Watanabe, and Fumiko Hamaguchi

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

Abstract

One-pot reactions of l-alkoxycarbonyl-2-hydroxypyrrolidines and -piperidines with Wittig reagents stabilized by carbonyl groups give α-alkylated pyrrolidines and piperidines in good yields. The syntheses of (±)-hygrine and (±)-2-epilasubine II using the Wittig products are described.

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Paper | Regular issue | Vol 29, No. 1, 1989, pp. 165 - 180
Published online:
DOI: 10.3987/COM-88-4746
Tautomerism of Bis(2-bensothiazolyl)arylmethanes

M. Teresa Ramos, Carmen Avendaño,* José Elguero, M. Luisa Jimeno, Juana Bellanato, Feliciana Florencío, and Julia Sanz-Aparicio

*Departamento de Química Orgánica y Farmacéutica, Facultad de Farmacia, Universidad Complutense de Madrid, Ciudad Universitaria, 28040 Madrid, Spain

Abstract

Tautomerism of some bis(2-benzothiazoly1)methanes has been studied by 1H nuclear magnetic resonance, ultraviolet, and infrared spectroscopies using C-methyl and N-methyl derivatives as model compounds of the “CH” and “NH” fixed forms. X-Ray diffraction analysis of compound 6 shows that it corresponds to the Z-sE isomer b2. The presence of two 2-benzothiazolyl groups is necessary for the “NH” tautomer to be stable.

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Paper | Regular issue | Vol 29, No. 1, 1989, pp. 181 - 184
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DOI: 10.3987/COM-88-4761
New Total Synthesis of Patulin

Julio A. Seijas, M. Pilar Vázquez Tato, Ramón Estévez, Luis Castedo, and Ricardo Riguera*

*Departamento de Química Orgánica, Sección de Alcaloides del C.S.I.C, Facultad de Química, Universidad de Santiago, 15706 Santiago de Compostela, Spain

Abstract

The total synthesis of the mycotoxin patulin from L-arabinose is described.

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Paper | Regular issue | Vol 29, No. 1, 1989, pp. 185 - 193
Published online:
DOI: 10.3987/COM-88-4766
Mass Spectometric Fragmentation of the Protonated Sydnones under Chemical Ionization

Ling-ling Tien, Shaw-Tao Lin,* and Hui-Jean Chiang

*Department of Applied Chemistry, Providence University, 200 Chungchi Road, Sha-Lu, Taichung Hsien, 433, Taiwan, R.O.C.

Abstract

The chemical ionization spectra of twenty protonated sydnones were measured by using methane a s a reagent gas. The intense fragmentation reaction takes place from the rupture of the sydnone ring by losing of HNO and CO molecules except for 3-benzylsydnones. The benzylsydnones yield the benzylic (tropylium) cations as the base peak. The NH+4 protonated 3-phenylsydnone results in [M+1]+[M+H+NH3]+ and [M+H+2NH3]+ as the principal peaks without any significant fragmentations.

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Paper | Regular issue | Vol 29, No. 1, 1989, pp. 195 - 202
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DOI: 10.3987/COM-88-4771
On the Structure of Sanggenon Q, A New Diels-Alder Type Adduct from Morus mongolica Schneider

Jin Yun Sun, Yoshio Hano, and Taro Nomura*

*Faculty of Pharmaceutical Sciences, Toho University, 2-2-1, Miyama, Funabashi, Chiba 274-8510, Japan

Abstract

A novel Diels-Alder type adduct, sanggenon Q (1), was isolated f from Morus mongolica Schneider (Moraceae) along with fourteen kinds of known phenolic compounds. Structure of sanggenon Q was shown to be 1 on the basis of spectral evidence. Sanggenon Q (1) is regarded biogenetically as a variation of a Diels-Alder type adduct, such as sanggenon C (2).

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25 data found. 1 - 25 listed