Regular Issue

Vol. 34, No. 1, 1992

20 data found. 1 - 20 listed
Communication | Regular issue | Vol 34, No. 1, 1992, pp.1-4
Published online:
DOI: 10.3987/COM-91-5836
Spectroscopic Characterizations of meso-Phenyl Substituted Tetrabenzoporphyrin Zinc Complexes

Ru-Jen Cheng,* Yu-Ran Chen, and Chang-Er Chuang

*Department of Chemistry, National Chung-Hsing University, Taichung, 40227, Taiwan, R.O.C.

Abstract

Zinc complexes of tetrabenzoporphyrin with mono-, di-, tri-, and tetraphenyl substituents at meso-position show electronic spectra with progressive red shifts from those of tetrabenzoporphyrin zinc complex, and these shifts may be related to ruffling of the macrocycle revealed by crystal structure determination. Fluorescence emissions and basicities of these compounds are also effected by this nonplanarity.

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Communication | Regular issue | Vol 34, No. 1, 1992, pp.5-11
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DOI: 10.3987/COM-91-5857
Additional Bioactive Neolignans from the Roots of Endlicheria dysodantha

Wen-wen Ma, Jon E. Anderson, Jerry L. McLaughlin,* and Karl V. Wood

*Department of Medicinal Chemistry and Pharmacognosy, School of Pharmacy and Pharmacal Sciences, Purdue University, West Lafayette, Indiana 47907, U.S.A.

Abstract

Three additional new neolignans, dysodanthins D, E, and F. and one known neolignan, megaphyllone acetate, have been isolated from the ethanol extract of the roots of Endlicheria dysodantha (Lauraceae). Their structures were solved using spectral data. Results of biological testing suggest further evaluation of megaphyllone acetate as an antitumor agent.

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Communication | Regular issue | Vol 34, No. 1, 1992, pp.13-16
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DOI: 10.3987/COM-91-5892
Synthetic Studies on Indole Alkaloids. V. Synthesis of 2-Methyleneindolo[2,3-a]quinolizidines

Anna Diez, David Miguel, Cristina Vila, Mario Rubiralta*, Roland Remuson, and Yvonne Gelas-Mialhe

*Laboratory of Organic Chemistry, Faculty of Pharmacy, University of Barcelona, 08028 Barcelona, Spain

Abstract

A synthesis of 2-methyleneindolo[2,3-a]quinolizidine (6) by the intramolecular cyclization of N-(2-hydroxyethyl)-2-[1-(phenylsulfonyl)-3-indolyl]-4-methylenepiperidine (9) by the action of t-C4H9OK is reported.

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Communication | Regular issue | Vol 34, No. 1, 1992, pp.17-20
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DOI: 10.3987/COM-91-5903
(R)-(+)-Noranicanine, a New Type of Trioxygenated Benzylisoquinoline. Isolation and Synthesis

Jean Michel Oger, Olivier Duval, Pascal Richomme, Jean Bruneton, Hélène Guinaudeau,* and Alain Fournet

*CEPM, UFR des Sciences Médicales et Pharmaceutiques, 16 Boulevard Daviers, 49045 Angers, France

Abstract

(R)-(+)-Noranicanine (1a), a new type of benzylisoquinoline precursor was isolated from Aniba canelilla (Lauraceae) and its structure was determined by means of spectroscopic data as well as by synthesis.

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Communication | Regular issue | Vol 34, No. 1, 1992, pp.21-24
Published online:
DOI: 10.3987/COM-91-5920
Synthesis and Absolute Configuration of the Green Alga Cytokinin 2-Hydroxy-1'-methylzeatin

Tozo Fujii,* Masashi Ohba, Tsuyoshi Haneishi, Satoshi Matsubara, A. H. Abad Farooqi, and Y. N. Shukla

*Faculty of Pharmaceutical Scicences, Kanazawa University, 13-1 Takara-machi, Kanazawa 920, Japan

Abstract

The correctness of the gross structure of the marine green alga cytokinin 2-hydroxy-1'-methylzeatin (1) has been confirmed as a result of the chiral syntheses of (1'R)-1 and (1'S)-1. An indirect comparison of the cytokinin activity of the natural cytokinin with those of the synthetic enantiomers suggests that the R configuration may be assigned to the natural one unless it would be racemic.

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Paper | Regular issue | Vol 34, No. 1, 1992, pp.25-36
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DOI: 10.3987/COM-91-5782
Synthesis and Reactions of 3-(3'-Thione)-1',2',4'-triazol-5'-ylcoumarin

Ahmed El Farargy, Fathi Yassin, Essam Abdel-Chani, Nadia El-Said, and Refaat Saleh*

*Faculty of Engineering, Suez Canal University, Port Said, Egypt

Abstract

3-(3'-Thione)-1',2',4'-triazol-5'-ylcoumarin (1) was prepared via condensation of 3-ethoxycarbonylcoumarin with thiosemicarbazide in boiling pyridine. The reaction of coumarin (1) with primary amines and hydrazines takes place by nucleophilic attack on the thione group to give 3-(3'-amino)-1',2',4'-triazol-5'-ylcoumarins (2a or 2b) and 3-(3'-hydrazinyl)-1',2',4'-triazol-5-ylcoumarins (2c-d). Condensation of 2c with aromatic aldehydes gave the correspoding 3-(3'-arylidenehydrazonyl)-1',2',4'-triazol-5'-ylcoumarins (3a-g). Alkylation of coumarin (1) with methyl iodide and ethyl chloroacetate gave 3-(1'-methyl-3'-methylthio)-1',2',4'-triazol-5'-ylcoumarin (8) and 3-(3'-ethoxycarbonylmethylthio)-1',2',4'-triazol-5'-ylcoumarin (9) respectively. Addition of compound (1) to acrylonitrile or methyl vinyl ketone under Michael addition conditions afforded the 3-[3'-(2"-cyanoethylthio)]-1',2',4'-triazol-5'-ylcoumarin (11a) and 3-[3'-(3-oxobutylthio)]-1',2',4'-triazol-5'-ylcoumarin (11b) and addition of (1) to Schiff bases afforded 3-[3'-(α-arylaminobenzylthio)]-1',2',4'-triazol-5'-ylcoumarins (12a-c). The antibacterial and antifungal activities of some compounds have been described.

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Paper | Regular issue | Vol 34, No. 1, 1992, pp.37-49
Published online:
DOI: 10.3987/COM-91-5810
Intramolecular Cyclization of Allylsilyl Substituted N-Acyliminium Ions. Access to 1- and 2-Azabicyclo[X.Y.0]alkanes. Total Synthesis of (±)-Mesembrine

Yvonne Gelas-Mialhe, Jean-Claude Gramain, Hassane Hajouji, and Roland Remuson*

*Laboratoire de Chimie des Substances Naturelles, URA CNRS 485, Université Blaise Pascal (Clemont-II), 63177 Aubière Cedex, France

Abstract

Access to 1- and 2-azabicyclo[x.y.0]alkanes by intramolecular cyclization of allylsilanes on α-acyliminium ions is described. This methodology is also used to achieve a highly stereoselective total synthesis of (±)-mesembrine.

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Paper | Regular issue | Vol 34, No. 1, 1992, pp.51-60
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DOI: 10.3987/COM-91-5833
Polycondensed Heterocycles. VIII. Synthesis of 11-Aryl-5H,11H-pyrrolo[2,1-c][1,4]benzothiazepines by Pummerer Rearrangement-Cyclization Reaction

Antonio Garofalo, Giuseppe Campiani, Vito Nacci,* and Isabella Fiorini

*Dipartimento Farmaco Chimico Technologico, Università di Siena, Banchi di Sotto, 55 - 53100 Siena, Italy

Abstract

11-Phenyl-5H,11H-pyrrolo[2,1-c][1,4]benzothiazepine has been prepared by an intramolecular nucleophilic displacement reaction. The same compound, as well as some analogues thereof, were more conveniently obtained by Pummerer rearrangement-cyclization of sulfinyl precursors. The latter method was also effective for the synthesis of 4-phenyl-4H-pyrrolo[2,1-c][1,4]benzothiazine.

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Paper | Regular issue | Vol 34, No. 1, 1992, pp.61-66
Published online:
DOI: 10.3987/COM-91-5847
Reactions of 3-Formylindole N,N-Dimethylhydrazones with Dienophiles. A Stereospecific Addition

Salvador Escrivá Moscardó, José Sepúlveda-Arques,* Belén Abarca Gonzalez, Rafael Ballesteros Campos, Concepción Soriano Soto, Santiago García Granda, and Fermín Gomez Beltran

*Departamento de Química Orgánica, Facultad de Farmacia, Universidad de Valencia, Valencia, Spain

Abstract

3-Formyl-1-methylindole N,N-dimethylhydrazone (1a) and 3-formylindole N,N-dimethylhydrazone (1b) react with methyl propiolate to give 3-cyano-1-methylindole (2a) and 3-cyanoindole (2b) respectively. When dimethyl acetylenedicarboxylate was used as a reagent the hydrazone (1a) afforded the nitrile (2a) and the pyridine (3) but in the reaction of the hydrazone (1b) an enantiomeric mixture of R,R and S,S dimethyl 1-(3-cyano-1-indolyl)-2-dimethylaminosuccinates (4) were obtained and their structures confirmed by X-ray single crystal analysis.

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Paper | Regular issue | Vol 34, No. 1, 1992, pp.67-83
Published online:
DOI: 10.3987/COM-91-5882
Anionic 4+2 Cyclization Route to 3-Sulfur Substituted Isocephem Analogs

Sagar Shakya and Tony Durst*

*Ottawa-Carleton Chemistry Institute, Department of Chemistry, University of Ottawa, Ottawa, Ontario, K1N 6N5, Canada

Abstract

Four different isocephem analogs have been synthesized. The key step in the construction of the bicyclic ring involves an anionic 4+2 cyclization. The lithio derivative obtained from a suitably protected N-carboxymethyl-2-azetidinone was condensed with carbon disulfide. Subsequent intramolecular alkylation of the 4-tosyloxymethyl substituent by the resultant sulfur nucleophile completed the cyclization sequence.

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Paper | Regular issue | Vol 34, No. 1, 1992, pp.85-97
Published online:
DOI: 10.3987/COM-91-5891
Four New Isoprenoid-substituted Dibenzoylmethane Derivatives, Glyineflanins A, B, C, and D from the Roots of Glycyrrhiza inflata

Lu Zeng, Toshio Fukai, Takae Kaneki, Taro Nomura,* Ru-Yi Zhang, and Zhi-Cen Lou

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

Abstract

Four new isoprenoid-substituted dibenzoylmethane derivatives, glyinflanins A (1), B (2), C (3), and D (4) were isolated from the roots of Glycyrrhiza inflata. The structures of glyinflanins A -D were elucidated by spectroscopic and chemical methods.

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Paper | Regular issue | Vol 34, No. 1, 1992, pp.99-102
Published online:
DOI: 10.3987/COM-91-5894
The Synthesis of 1-Amino-3,8-dipyridylmethyl-7-methylisoquinoline Involving a Tandem Addition Rearrangement Aryne Reaction

Abdul Rakeeb Deshmukh and Edward R. Biehl*

*Department of Chemistry, Southern Methodist University, Dallas, Texas 75275-0314, U.S.A.

Abstract

The synthesis of 1-amino-3,8-dipyridylmethyl-7-methylisoquinoline (3) accomplished by the reaction of 2-chloro-1,4-dimethylbenzene with pyridylacetonitrile under aryne forming conditions is reported. A mechanism is suggested in which a cyano group is introduced ortho to one of the ring methyl groups via a tandem-addition rearrangement aryne process. Such positioning of the cyano group facilitates lithiation of the adjacent methyl group by stabilizing the resulting CH2Li group by resonance delocalization. The CH2Li group then reacts with another molecule of pyridylacetonitrile affording a cyano-imine intermediate which condenses intramolecularly to afford 3 after a successive tautomeric shift and proton quench.

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Paper | Regular issue | Vol 34, No. 1, 1992, pp.103-110
Published online:
DOI: 10.3987/COM-91-5897
A Simple Route to 2,3-Dihydronaphtho[1,2-b]thiophenes and Naphtho[1,2-b]thiophenes Bearing Trifluoromethyl Groups by Aromatic Nucleophilic Substitution of N,N-Dimethyl-2,4-bis(trifluoroacetyl)-1-naphthylamine

Etsuji Okada, Ryoichi Masuda, Masaru Hojo,* Naonori Imazaki, and Hiroshi Miya

*Department of Industrial Chemistry, Faculty of Engineering, Kobe University, Kobe 657, Japan

Abstract

2,3-Dihydronaphtho[1,2-b]thiophenes (2, 4, 5, and 7) and naphtho[1,2-b]thiophenes (3 and 8) bearing trifluoromethyl groups were easily synthesized by aromatic nucleophilic nitrogen-sulfur exchange reaction of N,N-dimethyl-2,4-bis(trifluoroacetyl)-1-naphthylamine (1) with thioglycolic acids and with benzyl mercaptan, followed by cyclization (cyclodehydration).

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Paper | Regular issue | Vol 34, No. 1, 1992, pp.111-119
Published online:
DOI: 10.3987/COM-91-5898
Synthesis of 2-(Indol-3-yl)methyl-5-methylpyrazines, the Skeleton of Astechrome

Akihiro Ohta,* Hao Jing, Atsushi Maeda, Yasuyo Arai, Mikiko Goto, and Yutaka Aoyagi

*Tokyo College of Pharmacy, 1432-1 Horinouchi, Hachioji, Tokyo 192-03, Japan

Abstract

By the coupling reaction between indolyl-magnesium bromide and 2-tosyloxymethyl-5-methylpyrazines, three 2-(indol-3-yl)-5-methylpyrazines were synthesized. These compounds constitute the skeleton of astechrome, an iron-containing metabolite of Aspergillus terreus IFO 6123 and 8835.

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Paper | Regular issue | Vol 34, No. 1, 1992, pp.121-128
Published online:
DOI: 10.3987/COM-91-5901
Synthesis, Glycosidation and Resolution of (±)-Lomatin

Alexios-Léandros Skaltsounis, Sofia Mitaku, Gilbert Gaudel, François Tillequin, and Michel Koch*

*Laboratoire de Pharmacognosie, URA au CNRS n1310, Faculté des Sciences Pharmaceutiques et Biologiques, Université René Descartes, 4 Avenue de l'Observatoire, F-75006 Paris, France

Abstract

The first resolution of a racemic hydroxydihydropyranocoumarin, (±)-lomatin (1) was achieved by means of glycosidation, followed by separation of the diastereoisomeric glycosides and subsequent acid hydrolysis.

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Paper | Regular issue | Vol 34, No. 1, 1992, pp.129-134
Published online:
DOI: 10.3987/COM-91-5904
Electrochemical Formation of Indazoles from Tropone Tosylhydrazones: Electrochemical Oxidations of Sodium Salts of Tosylhydrazones of Tropone and 2-Phenyltropone

Katsuhiro Saito,* Masashi Hattori, Tatsuji Sato, and Kensuke Takahashi

*Department of Applied Chemistry, Nagoya Institute of Technology, Gokiso-cho, Showa-ku, Nagoya 466, Japan

Abstract

Electrochemical oxidations of the sodium salts of tropone and 2-phenyltropone tosylhydrazones afforded 2-tosyl-2H-indazole and 1-tosyl-7-phenyl-1H-indazole, respectively. The reactions proceeded through the cyclizations of the corresponding hydrazyl radicals generated by electrochemical one electron oxidations of the hydrazone anions.

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Paper | Regular issue | Vol 34, No. 1, 1992, pp.135-148
Published online:
DOI: 10.3987/COM-91-5906
Synthesis and Rearrangement of Aminoalkyl Lactones to Spirocyclic Hydroxymethyl Lactams

Claudia Dostal, Silvia Lauritz, and Ernst Urban*

*Institut für Pharmazeutische Chemie, Universität Wien, Währinger Strasse, A-1090 Wien, Austria

Abstract

Lithiation of lactones (1) and (2) followed by electrophilic substitution with dibromoalkanes afforded bromoalkyl lactones (3a -3c) and (4a - 4c). Treatment of 3a, 3b, 4a, and 4b with primary amines led to formation of aminoalkyl lactones (5a, 5b, 6a, 6b amd 11), which were rearranged to spirocyclic hydroxyalkyl lactams (7a, 7b, 8a, 8b and 12). Spirocyclic lactams (7a, 7b, 8a and 8b) were reduced to spirocyclic amines (9a, 9b, 10a and 10b), whereas reduction of lactam (12) gave a separable mixture of amine (13) and tricyclic aminal (15).

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Paper | Regular issue | Vol 34, No. 1, 1992, pp.149-156
Published online:
DOI: 10.3987/COM-91-5907
A Convenient Synthesis of 3(2)-Trifluoroacetylaminobenzo[b]thiophenes and Thiophenes and Some of Their Iodo Derivatives

Montserrat Prats* and Carmen Gálvez

*Departament de Química Orgánica, Facultat de Química, Universitat de Barcelona, Martí i Franquès 1-11, 08028 Barcelona, Spain

Abstract

Trifluoroacetylamino derivatives of benzo[b]thiophene (3a-d) have been obtained by Curtius rearrangement of the corresponding acyl azides (1a-d) with trifluoroacetic acid. The iodination of these amide derivatives with iodine under mild conditions leads to iodinated products in excellent yield, except in the case of the 3-trifluoroacetylaminobenzo[b]thiophene (3a), which only gives a polymeric residue.

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Paper | Regular issue | Vol 34, No. 1, 1992, pp.157-171
Published online:
DOI: 10.3987/COM-91-5908
New Tetrahydrofuranoid Steroidal Alkaloids from the Leaves of Buxus hildebrandtii

Atta-ur-Rahman,* M. Iqbal Choudhary,* Athar Ata, and Ermais Dagne

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

Abstract

Four new tetrahydrofuranoid steroidal alkaloids, (+)-O6-buxafuranamine (1), (+)-2-dehydroxy-O2-buxafuranamine (2), (-)-O10-buxafuranamine (3) and (-)-6-dehydroxy-O10-buxafuranamine (4) have been isolated from the leaves of Buxus hildebrandtii. These are the members of a new series of Buxus steroidal bases containing a tetrahydrofuran ring incorporated in their structures. The structures were established on the basis of extensive spectroscopic studies. Three new classes along with several more examples of the previously mentioned structural classes have been included in the rules which relates the structural features with the specific rotations.

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Paper | Regular issue | Vol 34, No. 1, 1992, pp.173-180
Published online:
DOI: 10.3987/COM-91-5934
Resolution of Racemic O-(4-Methoxyphenyl)glycidol

Seiichi Takano,* Masaki Setoh, and Kunio Ogasawara

*Pharmaceutical Institute, Tohoku University, Aobayama, Sendai 980, Japan

Abstract

Racemic O-(4-methoxyphenyl)glycidol has been resolved in three steps by employing lipase mediated kinetic acylation of the halohydrin intermediates

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20 data found. 1 - 20 listed