Regular Issue

Vol. 48, No. 3, 1998

19 data found. 1 - 19 listed
Communication | Regular issue | Vol 48, No. 3, 1998, pp.421-425
Published online:
DOI: 10.3987/COM-97-8064
Concentration Effect on the Stereoselectivity of [4+2] Cycloaddition Reactions of 3-Cyano-γ-benzopyrone Derivatives with Electron Rich Dienes

Richard P. Hsung*

*Department of Chemistry, Institute of Technology, University of Minnesota, Kolthoff and Smith Halls 207 Pleasant Street S. E. Minneapolis, MN 55455-0431, U.S.A.

Abstract

The stereoselectivity of [4+2] cycloaddition reactions of 3-cyano-γ-benzopyrone derivatives with electron rich dienes was found to be influenced by the reaction concentrations of γ-benzopyrone derivatives.

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Communication | Regular issue | Vol 48, No. 3, 1998, pp.427-431
Published online:
DOI: 10.3987/COM-97-8066
New Approach to (3R,4R)-3-Amino-N-benzyloxycarbonyl-4-hydroxy-hexahydro-1H-azepine Using Ring Expansion of Optically Active Piperidine Derivative

Toshiya Morie and Shiro Kato*

*Discovery Research Laboratories, Dainippon Pharmaceutical Co., Ltd., Enoki 33-94, Suita, Osaka 564, Japan

Abstract

New approach to (3R, 4R)-3-amino-N-benzyloxycarbonyl-4-hydroxyhexahydro-1H-azepine (18), which is the intermediate of the natural product balanol (1), is described. A key step in this method is ring expansion of the optically active piperidine derivative (10) to the corresponding hexahydro-1H-azepine (12) with retention of the configuration.

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Communication | Regular issue | Vol 48, No. 3, 1998, pp.433-436
Published online:
DOI: 10.3987/COM-97-8071
Stable Antiaromatic 1,4-Diazapentalenes: Synthesis and Oxidation Reaction of 2-Vinyl- and 2,5-Divinyl-1,4-dihydropyrrolo[3,2-b]pyrrole Derivatives

Kyosuke Satake,* Daizo Nakoge, and Masaru Kimura

*Department of Chemistry, Faculty of Science, Okayama University, 3-1-1 Tsushima-naka, Okayama 700-8530, Japan

Abstract

Stabel and isolable 8π electrons antiaromatic compounds, 2-vinyl and 2,5-divinyl substituted 1,4-diazapentalenes were synthesized via an oxidation reaction of correspondingly substituted 1,4-dihydro-3,6-di-tert-butylpyrrolo[3,2-b]pyrroles which were prepared by an electrophilic addition reaction of dimethyl acetylenedicarboxylate (DMAD).

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Communication | Regular issue | Vol 48, No. 3, 1998, pp.437-441
Published online:
DOI: 10.3987/COM-97-8074
Efficient Phenylsulfenylation and Phenylselenenylation at the 5-Position of Uracil Nucleosides with Disulfide and Diselenide Mediated by [Bis(trifluoroacetoxy)-iodo]benzene

Kyoung Rok Roh, Hye Kyung Chang, and Yong Hae Kim*

*Department of Chemistry, Korea Advanced Institute of Science and Technology, 373-1, Kusung-Dong, Yusung-Gu, Taejon, 305-701, Korea

Abstract

A series of uracil nucleosides reacted with diphenyl disulfide or diphenyl diselenide in the presence of hypervalent iodine reagent, [bis(trifluoroacetoxy)iodo]benzene, in acetonitrile to give the corresponding C-5 phenylsulfenylated or phenylselenenylated products respectively in excellent yields.

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Paper | Regular issue | Vol 48, No. 3, 1998, pp.443-450
Published online:
DOI: 10.3987/COM-97-8046
Preparation and Spectroscopic Properties of Trichotomine Derivatives Bearing Sterically Hindered Acyl Groups on C-1 and -1'

Hajime Irikawa* and Yasuhiro Kobayashi

*Department of Chemisttry, Faculty of Science, Shizuoka University, Ohya, Shizuoka 422

Abstract

The absorption and 13C NMR spectra of 1,1’-diacyltrichotomine derivatives showed that the central C(2)=C(2’) double bond was twisted, and coplanarity of the 1,1’-diacyl groups and the trichotomine chromophore was hindered by steric interactions between the 1,1’-diacyl groups and the 3,3’-dicarbonyl groups.

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Paper | Regular issue | Vol 48, No. 3, 1998, pp.451-459
Published online:
DOI: 10.3987/COM-97-8050
Reaction of 4-Bromobenzyl-3-methyl-1,2-oxazin-6-ones with Primary Aliphatic Amines. Synthesis and Structural Determination of New Oxazine and Isoxazole Derivatives

Monique Bebot, Pascal Coudert, Fernand Leal, Jacques Métin, Vincent Gaumet, Sylvie Mavel,Catherine Rubat, and Jacques Couquelet*

*Laboratoire de Chimie Organique Thérapeutique, Groupe de Recherche en Pharmacochimie, Faculté de Pharmacie, Université de Clermont I, 28, Place Henri Dunant, B.P. 38, 63001 Clermont-Ferrand Cedex, France

Abstract

Reaction of 4-bromobenzyl-6H-1,2-oxazin-6-ones (1) with aminoalkylamines furnished a mixture of 5-aminoalkylamino-6H-1,2-oxazine-6-ones (2), 4-(aminoalkylaminocarbonylmethyl)isoxazoles (3) and 5-(aminoalkylaminocarbonyl)isoxazoles (4) which were separated by column chromatography. Structure of all derivatives was determined by 1H- and 13C -NMR methods, including INEPT measurements. Structure of isoxazoles (3) and (4) was confirmed by X-Ray analysis. In addition, test compounds were investigated for analgesic and antidepressant activities in mice.

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Paper | Regular issue | Vol 48, No. 3, 1998, pp.461-464
Published online:
DOI: 10.3987/COM-97-8057
Silver(I) Ion-mediated Desulfurization-Condensation of Carbon Disulfide with Some Hydroxyl Compounds

Isao Shibuya,* Yasuo Gama, and Masao Shimizu

*National Institute of Materials and Chemical Research, 1-1-1 Higashi, Tsukuba, Ibaraki 305-8565, Japan

Abstract

The title reaction with ethanol and phenol gave tetraethyl and tetraphenyl orthocarbonate, respectively, in good yields. Diols, such as benzene-1,2-dimethanol, meso-hydrobenzoin, and cathecol, afforded spiro orthocarbonic acid esters. In the same manner, 2-anilinoethanol, N-methylanthranilic acid, and salicylic acid led to some novel spirobicyclces.

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Paper | Regular issue | Vol 48, No. 3, 1998, pp.465-480
Published online:
DOI: 10.3987/COM-97-8059
Mn(III)-based Reaction of Alkenes with Pyrrolidinedione Derivatives. Formation of Bicyclic Peroxides and the Related Compounds

Van-Ha Nguyen, Hiroshi Nishino,* and Kazu Kurosawa

*Department of Chemistry, Faculty of Science, Kumamoto University, Kurokami 2-39-1, Kumamoto 860-8555, Japan

Abstract

Alkenes (1) and 2,3-pyrrolidinediones (2) were treated with manganese (III) acetate in acetic acid at 23 °C under a stream of dry air giving 1-hydroxy-8-aza-2,3-dioxabicyclo[4.3.0]nonan-9-ones (3) in good yields. The reaction at elevated temperature gave 4-ethenyl-2,3-pyrrolidinediones (6) and/or 4-alkyl-2,3-pyrrolidinediones (7) in good yields. A wide variety of 2,3-pyrrolidinediones having an alkoxycarbonyl, cyano, or acyl group at the 4-position were tested to delineate the scope and iminations of these reactions. The mechanisms for the formation of the products were also discussed.

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Paper | Regular issue | Vol 48, No. 3, 1998, pp.481-489
Published online:
DOI: 10.3987/COM-97-8061
Reaction of β-, γ-, and δ-Chloroalkanamides with Potassium tert-Butoxide in Tetrahydrofuran: Elimination, and Lactamization

Eng Chi Wang* and Huey-Jen Lin

*School of Chemistry, Kaohsiung Medical University, 100 Shin Chuen 1st Rd., Kaohsiung 80708, Taiwan, R.O.C.

Abstract

γ-and δ-Chloroalkanamides were found to undergo lactamization readily when treated with potassium tert-butoxide in tetrahydrofuran. Raising the reaction temperature may encourage SN2-displacement reaction. On the other hand β-chloroalkanamides only undergo elimination, followed by dimerization and trimerization of the acrylamide initially formed.

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Paper | Regular issue | Vol 48, No. 3, 1998, pp.491-498
Published online:
DOI: 10.3987/COM-97-8068
Syntheses of Novel Acyclic Nucleosides, 9-(4'-Hydroxy-2'-methylbut-1'-enyl)-adenine and Related Compounds

Changmei Cheng, Tetsuro Shimo, Kenichi Somekawa,* and Masanori Baba

*Department of Applied Chemistry and Chemical Engineering, Faculty of Engineering, Kagoshima University, Korimoto, Kagoshima 890, Japan

Abstract

An exploratory coupling reaction between adenine and a protected vicinal dibromo-intermediate was carried out to give the β,γ-unsaturated nucleoside analogues and a vinyl bromide derivative. Then a novel CuI catalytic coupling reaction between adenine and the vinyl bromide was successfully developed to afford an α,β-unsaturated acyclic nucleoside, 9-(4’-hydroxy-2’-methylbut-1’-enyl)adenine. All the above nucleosides were subjected to an anti-HIV-1 test.

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Paper | Regular issue | Vol 48, No. 3, 1998, pp.499-505
Published online:
DOI: 10.3987/COM-97-8069
Isolation of Two Unusual Tetrahydroisoquinoline-Monoterpene Glucosides from Alangium lamarckii as Possible Intermediates in the Non-enzymatic Formation of Alangimarine from Alangiside

Atsuko Itoh,* Takao Tanahashi, and Naotaka Nagakura

*Kobe Pharmaceutical University, Motoyamakita, Higashinada, Kobe 658-8558, Japan

Abstract

From the fruits of Alangium lamarckii, two new glucosides (3) and (4), which possessed unusual structures different from any known tetrahydroisoquinoline-monoterpene glucosides, have been isolated. Their structures were determined on the basis of spectroscopic and chemical methods. These same glucosides were also obtained by storage of alangiside (2) in MeOH for a prolonged period and glucoside (4) was further converted to alangimarine (1), a benzopyridoquinolizine alkaloid from this plant, by the usual treatment for isolation of alkaloids, suggesting the possibility of non-enzymatic formation of alangimarine (1) from alangiside (2) via the isolated glucosides (3) and (4).

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Paper | Regular issue | Vol 48, No. 3, 1998, pp.507-518
Published online:
DOI: 10.3987/COM-97-8073
A Synthesis of the Quinolizidine Alkaloids (±)-Lasubine I and (±)-Lasubine II

Valérie Bardot, Daniel Gardette, Yvonne Gelas-Mialhe, Jean-Claude Gramain, and Roland Remuson*

*Laboratoire de Chimie des Substances Naturelle, UMR 6504, Université Blaise Pascal (Clermont-Ferrand), 24, avenue des Landais 63177 Aubiére Cedex, France

Abstract

A total synthesis of (±)-lasubine I and (±)-lasubine II has been achieved in six steps from a β-hydroxyallylsilane synthon using intramolecular cyclization of allylsilane on N-acyliminium ion as a key step.

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Note | Regular issue | Vol 48, No. 3, 1998, pp.519-528
Published online:
DOI: 10.3987/COM-97-7966
New Triterpenoidal Alkaloids from the Leaves of Buxus papillosa

Atta-ur-Rahman,* Samina Naz, Athar Ata, and M. Iqbal Choudhary*

*International Centre for Chemical Sciences, H. E. J. Research Institute of Chemistry, University of Karachi, Karachi-75270, Pakistan

Abstract

Phytochemical investigations on the ethanolic extract of the leaves of Buxus papillosa of Pakistani origin have resulted in the isolation of two new triterpenoidal alklaloids, (-)-2α,16α-diacetoxy-9β,11β-epoxybuxamidine (1) and (+)-papillozine-C (2) along with one known triterpenoidal base, (-)-sempervirone (3) isolated for the first time from this species. The structures of these natural products were established through detailed specroscopic studies.

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Note | Regular issue | Vol 48, No. 3, 1998, pp.529-536
Published online:
DOI: 10.3987/COM-97-8011
2-Haloalkylidenepropanedinitriles in the Synthesis of Fused Pyrimidines

Chaitanya G. Dave* and Rina D. Shah

*Organic Synthesis Laboratory, M. G. Science Institute, P. O. Box 4007, Navrangpura, Ahmedabad 300 009, India

Abstract

A single step synthesis of various heterocycles such as 2-cyano-5-phenylpyrrolo[1,2-a]quinazolines (6), 5-phenyl-7-cyano-8,9,10,11-tetrahydroindolo[1,2-a]quinazoline (7), 2-cyanocyclopenta[4,5]thieno[3,2-e]pyrrolo[1,2-a]pyrimidin-5(4H)-ones (9) and 4-(2-amino-3-cyanopyrrolo-1-yl)-5-carbethoxythiazole-2-thiones (10) have been reported using 2-haloalkylidenepropanedinitriles (1) and (2) with 5-substitued 2-aminobenzophenones (3), 2-amino-3-carbethoxycyclopenta[4,5]thiophenes (4) and 3-substituted 4-amiono-5-carbethoxythiazole-2-thiones (5) respectively.

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Note | Regular issue | Vol 48, No. 3, 1998, pp.537-544
Published online:
DOI: 10.3987/COM-97-8037
Regio- and Diastereoselective 1,3-Diploar Cycloaddition of Imidazoline 3-Oxides to Styrene

Necdet Coskun* and Mustafa Ay

*Uludag University, Department of Chemistry, 16059-Bursa, Turkey

Abstract

Δ3-Imidazoline 3-oxides (1) underwent regio- and diastereoselective cycloaddition with styrene to give perhydroimidazo[1,5-b]isoxazoles (3). Thermally induced retro cycloaddition of compounds (3) was demonstrated.

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Note | Regular issue | Vol 48, No. 3, 1998, pp.545-547
Published online:
DOI: 10.3987/COM-97-8063
Synthesis of the 3a-(3-Indolyl)-1,2,3,3a,8,8a-hexahydropyrrolo-[2,3-b]indole Core of Leptosins D-F

David Crich,* Ewa Fredette, and William J. Flosi

*Department of Chemistry, University of Illinois at Chicago, 845 West Taylor St. , Chicago, IL 60607-7061, U.S.A.

Abstract

The Fischer indole reaction of aldehyde and phenyl hydrazine in the presence of zinc chloride smoothly provides the core structure of the leptosins D-F in good to excellent yield.

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Note | Regular issue | Vol 48, No. 3, 1998, pp.549-553
Published online:
DOI: 10.3987/COM-97-8079
Three New Coumarins from Clausena excavata

Keiko Nakamura, Yuko Takemura, Motoharu Ju-ichi,* Chihiro Ito, and Hiroshi Furukawa

*Faculty of Pharmaceutical Science, Mukogawa-Women's University, 11-68 Koushien Kyuban-Cho, Nishinomiya, Hyogo 663-8179, Japan

Abstract

Three new lactone coumarines named clauslactone-K (1), -L (3) and -M (4) were isolated from the twigs and leaves of Clausena excavata, collected in Sumatra, Indonesia and their structures were elucidated by spectroscopic analysis.

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Note | Regular issue | Vol 48, No. 3, 1998, pp.555-560
Published online:
DOI: 10.3987/COM-97-8090
Synthesis of 2-Trifluoromethyl-2,3,4,5-tetrahydro-1H-3-benzazepine Derivatives

Masami Kawase,* Masayuki Niwa, Masakatsu Nozaki, and Noboru Motohashi

*Faculty of Pharmaceutical Sciences, Josai University, 1-1 Keyakidai, Sakado, Saitama 350-0295, Japana

Abstract

2-Trifluoromethyl-3-benzazepines (6 and 8) were efficiently prepared from 1,2,3,4-tetrahydro-1-hydroxymethylisoquinoline (3) via ring expansion, utilizing a ring closure/ring opening strategy. Introduction of the trifluoromethyl group at 2-position in 7,8-dihydroxy-3-benzazepine (9) resulted in showing no affinity to dopamine D1 and D2 receptors.

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Review | Regular issue | Vol 48, No. 3, 1998, pp.561-584
Published online:
DOI: 10.3987/REV-97-489
s-Triazolo[3,4-b]-1,3,4-thiadiazole Derivatives

Zi-Yi Zhang* and Xiao-Wen Sun

*National Laboratory of Applied Organic Chemistry, Department of Chemistry, Lanzhou University, Lanzhou 730000, China

Abstract

This review surveys syntheses, reactivities, spectroscopic properties and biological activities of s-triazolo[3,4-b]-1,3,4-thiadiazole derivatives.

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19 data found. 1 - 19 listed