Regular Issue

Vol. 34, No. 4, 1992

22 data found. 1 - 22 listed
Communication | Regular issue | Vol 34, No. 4, 1992, pp.643-650
Published online:
DOI: 10.3987/COM-91-5963
Synthesis of Chiral 2-Aryl-4-piperidones

Mario Rubiralta,* Anna Diez, Cristina Vila, Josep Castells, and Isabel López

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

Abstract

The synthesis of chiral 2-(2-indolyl)- and 2-(3-indolyl)-4-piperidones by reaction of N,N-dimethyl-4-oxo-2-[1-(phenylsulfonyl)indolyl]piperidinium iodide and (R)-(-)-phenylglycinol is reported.

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Communication | Regular issue | Vol 34, No. 4, 1992, pp.651-656
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DOI: 10.3987/COM-91-5965
Importance of the 2-Hydroxy Group for the Reactions of an Acetate of a Naturally Occurring Prohibitin, 4-Acetoxy-2-hydroxy-2H-1,4-benzoxazin-3(4H)-one, with Nucleophiles

Takayoshi Ishizaki, Yuichi Hashimoto, and Koichi Shudo*

*Faculty of Pharmaceutical Sciences, The University of Tokyo, Tokyo 113, Japan

Abstract

A prohibitin, 2,4-dihydroxy-2H-1,4-benzoxazin-3(4H)-one, reacted readily with nucleophiles after 4-O-acetylation. The 2-hydroxy group is mandatory for the reactions. The plausible interpretation for the enhancing effect of the 2-hydroxy group on the benzoxazinone system's reactivity involves an acetal ring-opening and reclosure mechanism.

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Communication | Regular issue | Vol 34, No. 4, 1992, pp.657-661
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DOI: 10.3987/COM-92-9570
Nucleosides and Nucleotides. 110. [2,3]-Sigmatropic Rearrangement of the Allylic Selenides to Allylic Amines in Sugar Moiety of Pyrimidine Nucleosides: Synthesis of 3'-Amino-2',3'-dideoxy-2'-methylidenecytidine

Abdalla Alsyed A. Hassan and Akira Matsuda*

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

Abstract

An allylic alcohol system in 2'-deoxy-2'-methylideneuridine derivative (4) was converted into the allylic selenide, 2',3'-didehydro-2',3'-dideoxy-2'-phenylselenomethyl derivative (11), which was treated with NCS and tert-butyl carbamate to afford a [2,3]-sigmatropic rearrangement product (13). Transformation of the uracil moiety of 13 into cytosine provided access to the title compound (16).

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Communication | Regular issue | Vol 34, No. 4, 1992, pp.663-666
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DOI: 10.3987/COM-92-5973
Synthesis of Furan-fused 3-Sulfolene. A Stable Precursor to Furan Analogue of o-Quinodimethane

Ta-shue Chou* and Chung-Ying Tsai

*Institute of Chemistry, Academia Sinica, Taipei, Taiwan, R.O.C.

Abstract

Ultrasound-promoted zincation of 2-chloro-4-bromo-2-sulfolene (10) with benzoyloxyacetaldehyde (6), followed by base-induced hydrolysis, intramolecular conjugate addition and aromatization, gives the 3-sulfolene (4) which is a stable precursor to the furan analogue of o-quinodimethane.

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Communication | Regular issue | Vol 34, No. 4, 1992, pp.667-674
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DOI: 10.3987/COM-92-5974
Annoreticuin and Isoannoreticuin: Two New Cytotoxic Acetogenins from Annona reticulata

Yang-Chang Wu,* Fang-Rong Chang, Chang-Yi Duh, and Shang-Kwei Wang

*Natural Products Research Center and School of Pharmacy, Kaohsiung Medical College, Kaohsiung 80708, Taiwan, R.O.C.

Abstract

Two novel bioactive monotetrahydrofuran acetogenins, annoreticuin (1) and isoannoreticuin (2), have been isolated from the leaves of Formosan plant Annona reticulata L. (Annonaceae). The plane structures of these two new compounds were elucidated on the basis of 1H and 13C nmr data and by mass spectrometry. These two compounds showed selective cytotoxic activities for certain human tumor cell lines.

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Communication | Regular issue | Vol 34, No. 4, 1992, pp.675-677
Published online:
DOI: 10.3987/COM-92-5976
Novel N-10 to C-4 Oxygen Migration in the Acridine Ring System

Steven C. Zimmerman* and Zijian Zeng

*Department of Chemistry, 1209 West California Street, University of Illinois, Urbana, Illinois 61801, U.S.A.

Abstract

Treatment of 9-aryl-2,7-dimethoxyacridine-10-oxides with acetic anhydride results in a novel rearrangement to the corresponding 4-acetoxyacridines. The rearrangement offers a convenient synthetic route to polyoxygenated acridines.

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Communication | Regular issue | Vol 34, No. 4, 1992, pp.679-684
Published online:
DOI: 10.3987/COM-92-5984
Preparation of (1R,4R)-1-Methyl-2-(p-toluenesulfonyl)-5-phenylmethyl-2,5-diazabicyclo[2.2.1]heptane, Intermediate in a Synthesis of New Naphthyridones

Philippe Remuzon,* Massoud Massoudi, Daniel Bouzard, and Jean-Pierre Jacquet

*Bristol-Myers Squibb Pharmaceutical Research Institute, BP 62, Lognes, 77422 Marne-la-Vallee Cedex 2, France

Abstract

An efficient chiral synthesis of the (1R,4R)-1-methyl-2-(p-toluenesulfonyl)-5-phenylmethyl-2,5-diazabicyclo[2.2.1]heptane (2b) was performed using trans-4-hydroxy-L-proline as starting material. This bridged piperazine was used in the preparation of new naphthyridones (16) and (17).

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Communication | Regular issue | Vol 34, No. 4, 1992, pp.685-688
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DOI: 10.3987/COM-92-5986
Thermolysis of 3,6-Diaza- and 6-Aza-3-oxabenzo[g]tricyclo[3.3.0.02,4]octanes: Formation of Novel 4,1-Benzoxazocines

Jyoji Kurita, Katsuhiro Kikuchi, Toshiko Aruga, and Takashi Tsuchiya*

*Faculty of Pharmaceutical Sciences, Hokuriku University, Kanagawa-machi, Kanazawa 920-11, Japan

Abstract

Thermolysis of the 3,6-diazabenzo[g]tricyclo[3.3.0.02,4]octane (7) at 180 °C resulted in rearrangement to give the pyrroloindole (9), whereas flash vacuum pyrolysis of the 6-aza-3-oxabenzotricyclooctanes (8) at 530 °C resulted in both ring-expansion and rearrangement to afford the novel 4,1-benzoxazocines (10) and furoindoles (11).

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Paper | Regular issue | Vol 34, No. 4, 1992, pp.689-698
Published online:
DOI: 10.3987/COM-91-5791
Two New Withanolides from Withania somnifera

Atta-ur-Rahman,* S. Arshad Jamal, and M.Iqbal Choudhary*

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

Abstract

Two new withanolides, sominone (1α,3β,27-trihydroxy-22(R)-witha-5,24-dienolide) (1) and sominolide (4β,27-dihydroxy-14α,15α-epoxy-1-oxo-22-(R)-witha-2,24-dienolide) (2) were isolated from the herbs of Withania somnifera Dun. (Solanaceae). The elucidation of their structures is based on extensive spectroscopic studies.

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Paper | Regular issue | Vol 34, No. 4, 1992, pp.699-711
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DOI: 10.3987/COM-91-5834
The Synthesis and Spectral Properties of N-(3,4,5-Trimethoxybenzoyl)-3,6-dihydro-1,2-oxazines and N-(3,4,5-Trimethoxybenzoyl)tetrahydro-1,2-oxaziens

Henryk Labaziewicz,* Bob A. Howell, Karl R. Lindfors, and Rodney C. Mason

*Department of Chemistry, Central Michigan University, Mt. Pleasant, MI 48859, U.S.A.

Abstract

In an attempt to develop neurosedatives of enhanced pharmacological activity and lower side-effect toxicity than those currently available, a series of novel 3,4,5-trimethoxybenzamides derived from either 3,6-dihydro-1,2-oxazine or tetrahydro-1,2-oxazine has been synthesized and fully characterized spectroscopically.

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Paper | Regular issue | Vol 34, No. 4, 1992, pp.713-722
Published online:
DOI: 10.3987/COM-91-5888
5-Alkoxymethyl-1-hydroxyalkyluracils with Potential Anti-HIV Activity

Ahmed E.-S. Abdel-Megied, Mohammed S. Motawia, Erik B. Pedersen, and Carsten M. Nielsen

*Department of Chemistry, Odense University, DK-5230 Odense M, Denmark

Abstract

Acid catalyzed etherification of 5-hydroxymethyluracil (3) afforded the corresponding 5-alkoxymethyluracils (4a-h). Treatment of the sodium salt of compounds (4a-g) with 4-bromobutyl acetate afforded 1,3-bis-(4-acetyloxybutyl)- (5a-g) and 1-4-acetyloxybutyluracil derivatives (6a-g). Alkylation of 4h with 5-chloropentyl benzoate gave 1,3-bis-(5-benzoyloxypentyl)- (8) and 1-(5-benzoyloxypentyl)-5-t-butyloxymethyluracil (9). Ammonolysis of 6a-g and 9 at room temperature gave the corresponding hydroxyalkyl derivatives (7a-g and 10).

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Paper | Regular issue | Vol 34, No. 4, 1992, pp.723-728
Published online:
DOI: 10.3987/COM-91-5941
Thermal Conversion of Methyl 8-Vinyl-3-oxo-2-oxabicyclo[2.2.2]oct-5-en-6-carboxylates to Tetrahydrocoumarins and Methyl Benzoates

Takanao Matsui,* Yoh-ichi Matsushita, and Mitsuru Nakayama

*Faculty of Engineering, Miyazaki University, Gakuen-Kibanadai, Miyazaki 889-21, Japan

Abstract

Methyl 8-methyl- and 8-methoxy-8-vinyl-3-oxo-2-oxabicyclo[2.2.2]oct-5-en-6-carboxylates (3 and 5), prepared by the Diels-Alder reaction of methyl 2-oxo-2H-pyran-5-carboxylate with 2-methyl- and 2-methoxy-1,3-butadienes, were converted into methyl 9-methyl- and 9-methoxy-3-oxo-2-oxabicyclo[4.4.0]deca-4,8-diene-6-carboxylates (tetrahydrocoumarins) by a Cope rearrangement at about 140 °C, respectively. On the other hand, 3 and 5 were transformed into methyl 4-isopropyl- and 4-acetylbenzoates via the reaction of methyl tricyclo[3.2.1.02,7]oct-3-en-4-carboxylates at about 257 °C in the presence of Pd-C, respectively.

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Paper | Regular issue | Vol 34, No. 4, 1992, pp.729-737
Published online:
DOI: 10.3987/COM-91-5953
One Step Synthesis of 5-Bromo-2-chloro-6-hydroxy-4-[N-(2,3-dibromopropyl)-N-alkylamino]pyrimidines, Useful Intermediates for the Preparation of Pteridine Derivatives and Related Analogues

Maurizio Botta,* Raffaele Saladino, and Rosario Nicoletti*

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

Abstract

A simple synthesis of pteridine derivatives (12) and (13), 5-oxapteridines (10a-c) and 5-thiapteridine (15) via cyclization of the highly functionalized pyrimidinones (8a-c) is reported.

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Paper | Regular issue | Vol 34, No. 4, 1992, pp.739-745
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DOI: 10.3987/COM-91-5954
Synthesis of New Carbocyclic Analogues of Oxetanocin A and Oxetanocin G

Pascal Pecquet, François Huet,* Michel Legraverend,* and Emile Bisagni

*URA CNRS 1387, Institut Curie-Biologie, Batiment 110-112, Centre Universitaire, 91405 Orsay Cedex, France

Abstract

The synthesis of cis-3-amino-1-cyclobutanemethanol has been performed in six steps (59.6% yield) from cis-1,3-cyclobutanedicarboxylic anhydride. This allowed us to obtain two new carbocyclic analogues of oxetanocin A and oxetanocin G related to 7-deazaadenosine and 7-deazaguanosine

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Paper | Regular issue | Vol 34, No. 4, 1992, pp.747-756
Published online:
DOI: 10.3987/COM-91-5956
A New Synthesis of 7,12-Dihydro-12-phenyl-5H-6,12-methanodibenz[c,f]azocines via N-Benzyl-1,2,3,4-tetrahydro-4-phenylisoquinolin-4-ols

Masaru Kihara,* Minoru Kashimoto, Yoshimaro Kobayashi, and Yoshimitsu Nagao

*Faculty of Pharmaceutical Sciences, The University of Tokushima, Sho-machi, Tokushima 770, Japan

Abstract

7,12-Dihydro-12-phenyl-5H-6,12-methanodibenz[c,f]azocine derivatives were prepared from N-benzyl-1,2,3,4-tetrahydro-4-phenylisoquinolin-4-ols by an intramolecular Friedel-Crafts reaction.

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Paper | Regular issue | Vol 34, No. 4, 1992, pp.757-764
Published online:
DOI: 10.3987/COM-91-5958
A New Synthetic Method for the Synthesis of Hydroxylated Isoquinolines: Preparation of Methyl 6,7- and 7,8-Dihydroxyisoquinoline-3-carboxylates, Potential Protein-Tyrosine Kinase Inhibitors

Terrence R. Burke, Jr.,* Pamela L. Russ, and Victor E. Marquez

*Laboratory of Medicinal Chemistry, Developmental Therapeutics Program, Division of Cancer Treatment, National Cancer Institute, National Instututes of Health, Bethesda, MD 20892, U.S.A.

Abstract

Synthesis of potential protein-tyrosine kinase inhibitors (6c) and (6e) is presented as a general procedure for the preparation of polyhydroxylated isoquinolines. Key features of the method include selective hydroxyl protection of tetrahydroisoquinolines by O-acylation followed by aromatization using MnO2. Quantitative deprotection of resulting O-acylisoquinolines is achieved using methanolic HCl.

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Paper | Regular issue | Vol 34, No. 4, 1992, pp.765-770
Published online:
DOI: 10.3987/COM-91-5961
Haliclonol, a New Tetrahydropyranone from the Caribbean Sponge Haliclona hogarthi

Patrizia Ciminiello, Valeria Costantino, Ernesto Fattorusso,* Silvana Magno, and Alfonso Mangoni

*Dipartimento di Chimica delle Sostanze Naturali, Via D. Montesano 49, I-80131, Napoli, Italy

Abstract

Haliclonol (2), a unique hydroxylated tetrahydropyranone, was isolated from the Caribbean sponge Haliclona hogarthi, and its structure, including absolute stereochemistry, was elucidated by spectroscopic (ir, nmr, ms and cd) data.

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Paper | Regular issue | Vol 34, No. 4, 1992, pp.771-780
Published online:
DOI: 10.3987/COM-91-5962
The Synthesis of Spirocyclic [1,2,4]Triazolo[4,3-a]quinolines as Potential Ligands for the Benzodiazepine Receptor

Lawrence A. Reiter* and Gary E. Berg

*Central Research Division, Pfizer Inc, Groton, CT 06340, U.S.A.

Abstract

Two spirocyclic [1,2,4]triazolo[4,3-a]quinolines (1a and b) have been prepared as potential ligands for the benzodiazepine receptor. Both compounds were prepared using the strategy of doubly deprotonating an acetanilide derivative followed by reaction with α-tetralone. The resulting alcohols were converted to the corresponding spirocyclic 3,4-dihydroquinolin-2-one or -2-thione by treatment with neat HF. Triazole formation was effected by standard procedures. An alternate strategy starting with an intact triazole was unsuccessful but this route led to the first example of a lateral metallation of a 4-substituted 1,2,4-triazole.

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Paper | Regular issue | Vol 34, No. 4, 1992, pp.781-790
Published online:
DOI: 10.3987/COM-91-5964
A One-Pot Access to [b]Annellated Carbazoles as Potential DNA Intercalators via Diels-Alder Reactions with 1-Alkylpyrano[3,4-b]indol-3-ones

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

*Department of Chemistry and Pharmacy, University of Mainz, Saarstrasse 21, D-6500 Mainz 1, Federal Republic of Germany

Abstract

1-Alkylpyrano[3,4-b]indol-3-ones (3) react via a Diels-Alder process with arynes or N-phenylmaleimide to furnish [b]annellated carbazoles (4-10) in a one-pot procedure. Compounds (4-8) with a coplanar framework belong to the class of potential DNA intercalators.

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Paper | Regular issue | Vol 34, No. 4, 1992, pp.791-798
Published online:
DOI: 10.3987/COM-91-5969
Facile Synthetic Methods for 3- and 5-Trifluoromethyl-4-trifluoroacetylpyrazoles and Their Conversion into Pyrazole-4-carboxylic Acids

Etsuji Okada, Ryoichi Masuda, and Masaru Hojo*

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

Abstract

3- and 5-Trifluoromethyl-4-trifluoroacetylpyrazoles (4 and 5) were easily synthesized in excellent yields by reaction of β,β-bis(trifluoroacetyl)vinyl ethers 1, sulfides 2, and -amines 3 with hydrazines. Hydrolysis of these compounds (4 and 5) with aqueous potassium hydroxide gave the corresponding pyrazole-4-carboxylic acids (6 and 7) in high yields.

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Paper | Regular issue | Vol 34, No. 4, 1992, pp.799-806
Published online:
DOI: 10.3987/COM-92-5981
A Novel Synthesis of 6-Demethoxyacronycine

Abdelhakim Elomri, Sylvie Michel, François Tillequin, and Michel Koch*

*Laboratoire de Pharmacognosie de l'Université René Descartes, URA au CNRS n°1310, Faculté des Sciences Pharmaceutiques et Biologiques, 4, Avenue de l'Observatoire, F-75006 Paris, France

Abstract

The title compound was synthetized in six steps, starting from 3-nitrophenol. The key-step involves condensation of 2-bromobenzoic acid with 5-amino-2,2-dimethylchromene.

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Review | Regular issue | Vol 34, No. 4, 1992, pp.807-834
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DOI: 10.3987/REV-92-439
A Survey of 6,9-Epoxycyclodeca[b]furan Sesquiterpenes

Dearg S. Brown and Leo A. Paquette*

*Evans Chemical Laboratories, The Ohio State University, Columbus, Ohio 43210, U.S.A.

Abstract

The source, structure, and biological activities of the many known 6,9-epoxycyclodeca[b]furan natural products are compiled herein for ready reference.

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22 data found. 1 - 22 listed