Regular Issue

Vol. 27, No. 11, 1988

22 data found. 1 - 22 listed
Communication | Regular issue | Vol 27, No. 11, 1988, pp. 2517 - 2522
Published online:
DOI: 10.3987/COM-88-4624
Antimicrobial Agents from Higher Plants. The Isolation and Structural Characterization of Two Additional Pterocarpan Antimicrobial Agents from Nigerian Erythrina mildbraedii

Lester A. Mitscher,* Simon K. Okwute, Sitaraghav R. Gollapudi, and Ali Keshavarz-Shokri

*Department of Medicinal Chemistry, Kansas University, Lawrence, Kansas 66045, U.S.A.


Examination of bioactive mother-liquors from previous large scale experiments on the antimicrobial agents from the Nigerian medicinal plant, Erythrira mildbraedii, led to the isolation and structural characterization of two new pterocarpans, erybraedin D and E. Erybraedin D was initially isolated as its apparently artifactual hemiethyl phthalate ester. Both new pterocarpans possess marginal antimicrobial potency in vitro.

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Communication | Regular issue | Vol 27, No. 11, 1988, pp. 2523 - 2526
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DOI: 10.3987/COM-88-4672
‘Umpolung’ of Reactivity at C-5 Position of Uracil: An Unprecedented Nucleophilic Reaction of Thiolane Ion at C-5 of 6-Cyano-1,3-dimethyluracil

Subodh Kumar* and Swapandeep Singh Chimni

*Department of Applied Chemical Sciences & Technology, Guru Nanak Dev University, Amritsar 143 005, India


The soft thiolate ions react with 6-cyano-1,3-dimethyluracil at C-5 to give 5-alkylthio-1,3-dimethyluracil derivatives as major products.

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Communication | Regular issue | Vol 27, No. 11, 1988, pp. 2527 - 2529
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DOI: 10.3987/COM-88-4691
Regiospecific Preparation of 2-Oxazolines Promoted by Silicon Tetrafluoride

Makoto Shimizu* and Hirosuke Yoshioka*

*The Institute of Physical and Chemical Research, Wako-shi, Saitama 351-0198, Japan


Silicon tetrafluoride promotes reaction of oxiranes with nitriles to give 2-oxazolines in good yield.

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Communication | Regular issue | Vol 27, No. 11, 1988, pp. 2531 - 2534
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DOI: 10.3987/COM-88-4693
Intermolecular Heteroaromatic Nucleophilic Substitution Reaction via the Sulphur Ylide Rearrangement: C-Attack vs. O-Attack

Tetsuji Kametani,* Kuniaki Kawamura, Takeshi Akagi, Chikako Fujita, and Toshio Honda

*Hoshi University, 2-4-41 Ebara, Shinagawa-ku, Tokyo 142-8501, Japan


Intermolecular aromatic nucleophilic substitution reaction of the heterocyclic sulphide derivatives with α-diazo esters in the presence of rhodium (II) acetate was investigated to give the oxygen-introduced products via the sulphur ylide rearrangement.

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Communication | Regular issue | Vol 27, No. 11, 1988, pp. 2535 - 2537
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DOI: 10.3987/COM-88-4705
Synthesis of (2R,3S)-2-Hydroxymethyl-3-hydroxypyrrolidine and the Geissman-Waiss Lactone from (S)-Pyroglutamic Acid

Nobuo Ikoto* and Akira Hanaki

*National Institute of Radiological Sciences, 9-1, Anagawa-4-Chome, Inage-ku, Chiba 263-0024, Japan


The synthesis of (2R,3S)- and (2R,3R)-2-hydroxymethyl-3-hydroxypyrrolidine derivatives (5 and 7) and the Geisman-Waiss lactone (12) has been achieved from (S) -pyroglutamic acid.

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Communication | Regular issue | Vol 27, No. 11, 1988, pp. 2539 - 2544
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DOI: 10.3987/COM-88-4706
The Light Induced Conversation of Thieno[2,3-c]isothiazoles into Thiophenes

Antonino Corsaro, Francesco Guerrera, Maria C. Sarvà, and Maria Siracusa

*Istituto di Chimica Farmaceutica e Tosshicologica, Università di Catania, Viale A. Doria 6, I-95125 Catania, Italy


The sun light induced conversion of thieno[2,3-c]isothiazoles 1a-d into thiophenes 2a-d, with loss of elemental sulfur is reported. A presumable mechanism for the thiophene nucleus formation is discussed to involve the opening of the two heterocyclic rings with formation of an open-chain valence bond isomer through the initial homolytic cleavage of the isothiazole N-S linkage.

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Communication | Regular issue | Vol 27, No. 11, 1988, pp. 2545 - 2548
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DOI: 10.3987/COM-88-4708
Synthesis and Anti-HIV Activity of 3’-Cyano-2’,3’-dideoxythymidine and 3’-Cyano-2’,3’-didehydro-2’,3’-dideoxythymidine

Akira Matsuda,* Mutsumi Satoh, Hideki Nakashima, Naoki Yamamoto, and Tohru Ueda

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


3’-Cyano-2’,3’-dideoxy- and 3’-cyano-2’,3’-didehydro-2’,3’-dideoxythymidines (4,5) have been synthesized from 5-methyluridine (7). Anti-HIV activity of these compounds is also described.

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Communication | Regular issue | Vol 27, No. 11, 1988, pp. 2549 - 2556
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DOI: 10.3987/COM-88-4709
Asymmetric Electrophilic α-Amidoalkylation 5: Improved Stereoselectivities through New Chiral Auxiliaries

Klaus Th. Wanner,* Annerose Kärtner, and Elmar Wadenstorfer

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


Enamides of type 2 were employed in asymmetric α-amidoalkylation reactions with silyl enol ether 4 as nucleophile. Depending on the chiral auxiliary used, (R)-5/(S)-5 stereoselectivities up to 95/5 could be reached. Based on the obtained results a model for the transient acyliminium ion is proposed.

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Communication | Regular issue | Vol 27, No. 11, 1988, pp. 2557 - 2562
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DOI: 10.3987/COM-88-4733
Site Selectivity in the 1,3-Dipolar Cycloaddition Reaction of Unsymmetric Pyridinium Bis(methoxycarbonyl)methylides with Methyl Propiolate

Kiyoshi Matsumoto,* Yukio Ikemi, Hideyuki Konishi, Xiao-lan Shi, and Takane Uchida

*Graduate School of Human and Environmental Studies, Kyoto University, Yoshida-Nihonmatsu-cho, Sakyo-ku, Kyoto 606-8501, Japan


The 1,3-dipolar cycloaddition of.unsymmetric pyridinium bis(methoxycarbonyl)methylides with methyl propiolate proceeds in moderate to good yields with high to moderate site selectivity with respect to the ylide. Polar 3-substituted pyridinium bis(methoxycarbonyl)methlides generally gave predominantly the corresponding 8-substituted indolizines regardless of the substituents. The results can be explained by dipole-dipole interactions.

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Communication | Regular issue | Vol 27, No. 11, 1988, pp. 2563 - 2566
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DOI: 10.3987/COM-88-4744
Chemistry on Benzopentathiepin. Reactios of Benzopentathiepin with Aromatic Compounds in the Presence of Lewis Acid

Ryu Sato,* Akira Onodera, Takehiko Goto, and Minoru Saito

*Department of Applied Chemistry, Faculty of Engineering, Iwate University, 4-3-5 Ueda, Morioka, Iwate 020-8551, Japan


Benzopentathiepin (BPT) reacted with many aromatic compounds such as benzene, 1,4-dimethylbenzene, and naphthalene in the presence of Lewis acid to give various thianthrenes in moderate yields. BPT was found to serve as a 1,4-dication synthon.

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Paper | Regular issue | Vol 27, No. 11, 1988, pp. 2567 - 2576
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DOI: 10.3987/COM-88-4495
On the Reactivity of 5(4H)-Oxazolones with Amines

Javier Blasco, Carlos Cativiela, María D. Díaz de Villegas, José I. García, Carlos Jaime, and José A. Mayoral

*Departamento de Quimica Organica, Facultad de Ciencias -I Instituto de Ciencia de los Materiales de Aragón, Universidad de Zaragoza, E-50009 Zaragoza, Aragon, Spain


Reactions of (Z/E)-2-phenyl-4-(α-arylethylidene)-5(4H)-oxazolones and Z-2-phenyl-4-arylmethylene-5(4H)-oxazolones with nucleophiles occur with retention of the exocyclic double band geometry, whereas reactions of E-2-phenyl-4-arylmethylene-5(4H)-oxazolones with some nucleophiles occur with total or partial isomerization. Structural calculations, MNPI and AM1, on model compounds reveal that the methyl group does not essentially affect the phenyl ring-double bond planarity. Application of the Klopman-Salem equation to the reaction of E-2-phenyl-4-benzylidene-5(4H)-oxazolone with different amines, calculated by MNDO, points to a reversible nucleophillc attack at the exocyclic carbon of this 5(4H)-oxazolone as a possible explanation of this behaviour. As Z-2-phenyl-4-benzylidene-5(4H)-oxazolone is more stable than the E-isomer, the opening reactions of the Z-compound occur without isomerization.

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Paper | Regular issue | Vol 27, No. 11, 1988, pp. 2577 - 2580
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DOI: 10.3987/COM-88-4550
Peculiar C-C Bond Cleavages of Pyrazolyl Propenone Epoxides Induced by Grignard Reagents

Ali El-Shekeil,* Abdulla Babaqi, Mohammed Hassan, and Sayed Shiba

*Chemistry Department, Faculty of Science, Sana‘s University, Sana‘s, Yemen


1-Aryl-3-(5-chloro-1,3-diphenyl-1H-4-pyrazalyl)prop-2-en-1-ones(2) yielded pyrazolylpropenone epoxides (3) on which peculiar C-C bond cleavages were induced by Grignard reagents giving the unexpected saturated secondary alcohols (4) bearing pyrazolyl nucleus.

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Paper | Regular issue | Vol 27, No. 11, 1988, pp. 2581 - 2588
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DOI: 10.3987/COM-88-4618
3,7-Bis(carbothoxy)perhydro-1,5,2,4,6,8-dithiatetrazocime 1,1,5,5-tetroxide. Synthesis, Structure and Chemistry

Chai-Ho Lee and Harold Kohn*

*Department of Chemistry, University of Houston, Houston, TX 77004, U.S.A.


The synthesis and single-crystal X-ray crystallographic analysis of 3,7-bis(carboethoxy)perhydro-1,5,2,4,6,8,-dithiatetrazocine 1,1,5,5-tetroxide (1) and the corresponding permethylated derivative 2 is detailed. The use of 1 in electrophilic aromatic substitution transformations with benzene, toluene, and anisole is also described.

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Paper | Regular issue | Vol 27, No. 11, 1988, pp. 2589 - 2594
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DOI: 10.3987/COM-88-4619
Xanthonolignoids from Hypericum subalatum

Ming-Tyan Chen*

*Department of Applied Chemistry, Chia Nan Junior College of Pharmacy, Tainan, 71710, Taiwan, R.O.C.


The isolation and characterization of three xanthonolignoids, kielcorin, cadensin D, and a new compound named as subalatin, from the whole plant of Hypericum subalatum Hayata are described.

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Paper | Regular issue | Vol 27, No. 11, 1988, pp. 2595 - 2607
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DOI: 10.3987/COM-88-4638
Selective Syntheses of Analogues of the Natural Precocenes. Synthesis and Regioselective O-Alkylation of 6-Chloro- and 6-tert-Butyl-7,8-dihydroxy-2,2-dimethyl-4-chromanones

Péter Sebök, Tibor Timár,* Joseph Csaba Jászberényi, and Gyula Batta

*Department of Research, Alkaloida Chemical Co. Ltd., H-4440 Tiszavasvári, POB 1, Hungary


The synthesis of novel benzopyran compounds 16 a-f, analogues of the natural precocenes (1 and 2) is described. These derivatives are obtained via novel synthesis and regioselective 0-alkylation of 6-chloro-and 6-tert-butyl-7,8-dihydroxy-2,2-dimethyl-4-chromanones (7 and 12).

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Paper | Regular issue | Vol 27, No. 11, 1988, pp. 2609 - 2618
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DOI: 10.3987/COM-88-4668
Chemistry of N-Chloronortropine Derivatives: Synthesis of a Bridgeed Aziridine Compound and New Tropane Derivatives

Syuichi Furuya* and Toshihiko Okamoto

*Central Research Division, Takeda Chemical Industries, Ltd., 17-85 Jusohonmachi 2-chome, Yodogawa-ku, Osaka 532-8686, Japan


An unsymmetrical bridged aziridine compound was obtained from N-chloronortropinone. This compound was found to react with acyl halides, acid anhydrides, and other reagents, including a Michael acceptor, dimethyl acetylenedicarboxylate (DMAD), giving new tropane bases with a ketone functional group at the bridged ethylene moiety. In the case of Michael-type addition, the retention of the aziridine ring system was observed in some solvents.

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Paper | Regular issue | Vol 27, No. 11, 1988, pp. 2619 - 2625
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DOI: 10.3987/COM-88-4684
Reactions of Triethyl[1-(N-tert-Butylimisoyl)-2-pyrrolinyl]borate with Electrophiles

Minoru Isikura and Masanao Terashima*

*Faculty of Pharmaceutical Scicences, Higashinihonngakuen University, 1757 Kanazawa, Toubetu-cho, Ishikari-gun, Hokkaodo 061-0212, Japan


The reaction of triethyl[1-(N-tert-butylimidoyl)-2-pyrrolinyl)borate (2) with alkyl halides, allylic bromides, alkenyliodonium salt, and N-carbophenoxypyridinium chloride in the absence or the presence of copper(I) ion were investigated.

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Paper | Regular issue | Vol 27, No. 11, 1988, pp. 2627 - 2633
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DOI: 10.3987/COM-88-4688
Diarryl-α-heteroarylmalonates from Cerium(IV)-promoted Reactions of Dialkyl Malonates with Heterocyclic Compounds

Leonard M. Weinstock,* Edward Corley, Newton L. Abramson, Anthony O. King, and Sandor Karady*

*Division of Merec and Co., Inc., Merck Sharp and Dohme Research Laboratories, Rahway, New Jersey 07065, U.S.A.


Thiophenes, furans and their benzo analogs undergo facile malonylation in the 2-position on reaction with dialkyl malonate radicals generated with cerium(IV) reagent.

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Paper | Regular issue | Vol 27, No. 11, 1988, pp. 2635 - 2641
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DOI: 10.3987/COM-88-4699
Synthesis of 2,4-Dioxoimidazolidines from 2-Arylimino-1,3-thiazines and Their Antifungal Activity

Mitsuhiro Ichinari, Kuniyoshi Nakayama, and Yoshio Hayase

*Aburahi Laboratories, Shionogi & Co. Ltd., Gotanda, Koka-cho, Koka-gun, Shiga 520-3423, Japan


2,4-Dioxoimidazolidines were obtained by the reaction of 2-arylimino-1,3-thiazines with chloroacetyl chloride (CAC) under aqueous alkaline conditions. Some derivatives of 2,4-dioxoimidazolidines exhibited antifungal activity against downy mildew.

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Paper | Regular issue | Vol 27, No. 11, 1988, pp. 2643 - 2650
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DOI: 10.3987/COM-88-4712
A Convenient Synthesis of Azaanthraquinones via Polar Addition to Hetaryne Intermediates. Use of Carbaninons Derived from 3-Cyano-1(3H)-isobenzofuranones

Subhash P. Khanapure and Edward R. Biehl

*Department of Chemistry, Southern Methodist University, P.O. Box 750314, Dallas, TX 75275-0314, U.S.A.


A convenient synthesisof 2-azaanthraquinones using the reaction of carbanions derived from 3-cyano-1(3H)-isobenzofuranones which serve as 1,4-dipole equivalents and hetaryne intermediates generated from bromopyridines and lithium diisopropylamide is reportted.

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Paper | Regular issue | Vol 27, No. 11, 1988, pp. 2651 - 2658
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DOI: 10.3987/COM-88-4747
Syntheses of Natural Coumarinolignans: Oxidative Coupling of 7,8-Dihydroxycoumarins and Phenylpropenes in the Presence of Diphenyl Selenoxide

Hitoshi Tanaka, Masaya Ishihara, Kazuhiko Ichino, and Kazuo Ito*

*Faculty of Pharmacy, Meijo University, 150 Yagoto, Tempaku-ku, Nagoya, Aichi 468-8503, Japan


Oxidative coupling of 7,8-dihydroxycoumarins (1, 2) and phenylpropenes (3-5) using Ph2Se0 as oxidizing agent resulted in remarkably efficient synthesis of naturally occurring coumarinolignans (cleomiscosin A (6A), aquillochin (cleomiscosin C)(6B), daphneticin (6C), and propacin (6D)).

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Review | Regular issue | Vol 27, No. 11, 1988, pp. 2659 - 2776
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DOI: 10.3987/REV-88-388
C-Substitution of Nitrogen Heterocycles

Helmut Vorbüggen* and Manfred Maas

*Research Laboratories, Schering AG, Berlin / Bergkamen, D-1000 Berlin 65, Germany


An attempt has been made to summarize, evaluate and compare the available methods for the introduction of C-substituents into aromatic nitrogen heterocycles. However due to the large number of publications on this topic this review is necessarily limited to the most important pubilcations.

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22 data found. 1 - 22 listed