Regular Issue

Vol. 27, No. 10, 1988

31 data found. 1 - 30 listed Next Last
Communication | Regular issue | Vol 27, No. 10, 1988, pp.2289-2292
Published online:
DOI: 10.3987/COM-88-4631
Synthetic Studies on Naulafine

David B. Repke,* Jahangir, Robin D. Clark, and Janis T. Nelson

*Institute of Organic Chemistry, Syntex Discovery Research, 3401 Hillview Avenue, Palo Alto, California 94304, U.S.A.

Abstract

The first synthesis of Naulafine, 7,12-dihydrocyclopent[de]indolo-[2’,3’:3,4]pyrido[1,2-b][2,7]- naphthyridin-4(6H)-one, is described.

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Communication | Regular issue | Vol 27, No. 10, 1988, pp.2293-2296
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DOI: 10.3987/COM-88-4633
Design and Synthesis of Photoresponsive Crown Ethers via Olefin Metathesis

Kenji Hayakawa, Ryo Naito, and Ken Kanematsu*

*Institute of Synthetic Organic Chemistry, Faculty of Pharmaceutical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan

Abstract

Crowned cage compounds (5 and 9), prepared from crowned p-benzoquinone and cyclopentadienes by the sequence of the Diels-Alder reaction end photochemical [2+2] cycloaddition, constitute a new class of photoresponsive systems based on the reversible [2+2] cycloreversion/cycloaddition.

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Communication | Regular issue | Vol 27, No. 10, 1988, pp.2297-2300
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DOI: 10.3987/COM-88-4635
Synthesis of 1,2,4-Triazolo Fused Heterocycles

Rajat B, Mitra,* Zainab Muljiani, and Sunita R. Deshpande

*National Chemical Laboratory, Poona-41108, India

Abstract

Synthesis of bicyclic and tetracyclic ring systems containing 1,2,4-triazole unit has been achieved by alkylation of substituted 1,2,4-triazoles followed by base catalysed cyclocondensation.

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Communication | Regular issue | Vol 27, No. 10, 1988, pp.2301-2304
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DOI: 10.3987/COM-88-4639
A Convenient Synthesis of Ethyl-β-dioxohydropyridinyl, Ethyl-β-dihydrodioxopyrido[3,2-c]pyridazinyl and Ethyl-β-oxopyranylacrylate Derivatives

Fathy M. Abdel Galil,* Obeys K. Hashim, and Sohair S. Saleh

*Department of Chemistry, Faculty of Science, University of Cairo, Giza, Egypt

Abstract

A variety of pyridine, pyrido[3,2-c]pyridazine and pyran derivatives was synthesized from the enamino-nitrile derivative diethyl 3-amino-2-cyano-2-pentenedioafe (1) as a starting material.

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Communication | Regular issue | Vol 27, No. 10, 1988, pp.2305-2308
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DOI: 10.3987/COM-88-4643
Reaction of N-Methyl-γ, δ-, and ε-lactams with t-Butyl Perbenzoate

Christopher J. Easton,* Steven C. Peters, and Stephen G. Love

*Department of Organic Chemistry, University of Adelaide, G.P.O. Box 498, Adelaide, S.A. 5001, Australia

Abstract

N-Methyl-γ-, δ-, and ε-lactams reacted with t-butyl perbenzoate to give, in each case, products of oxidation at endocyclic and exocyclic carbon adjacent to amide nitrogen.

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Communication | Regular issue | Vol 27, No. 10, 1988, pp.2309-2313
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DOI: 10.3987/COM-88-4650
On the Structure of Licoricidin

Toshio Fukai, Masafumi Toyono, and Taro Nomura*

*Faculty of Pharmaceutical Sciences, Toho University, Toho University

Abstract

A prenylated isoflavan isolated from Sipei licorice (Glycyrrhiza sp., Leguminosae, Seihoku Kanzo in Japanese) was proved to be identical with already known compound licoricidin (2). From the spectral data, the structure (2) of licoricidin should be revised to the structure (1).

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Communication | Regular issue | Vol 27, No. 10, 1988, pp.2315-2325
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DOI: 10.3987/COM-88-4652
Absolute Configuration of Natural Diels-Alder Type Adducts from the Morus Root Bark

Yoshio Hano, Shinkichi Suzuki, Taro Nomura,* and Yoichi Iitaka

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

Abstract

Absolute configuration of optically active Diels-Alder type adducts from the Morus root bark, which are regarded as adducts of chalcones and dehydroprenylphenols, were determined on the basis of X-ray crystallographic analysis and the cd spectra. Absolute configuration of the chiral centers on the methylcyclohexene ring in the cis-trans adducts was established to be 3”S, 4”R, 5”S, while in the all-trans adducts to be 3”R, 4”R, 5”S.

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Communication | Regular issue | Vol 27, No. 10, 1988, pp.2327-2330
Published online:
DOI: 10.3987/COM-88-4657
4-Dimethylaminopyridine N-Oxide as an Excellent Catalyst for Thione to Theol Rearrangement of Xathates

Kazunobu Harano, Hideo Kiyonaga, Shin-ichiro Sugimoto, Toshikazu Matsuoka, and Takuzo Hisano*

*Faculty of Pharmaceutical Sciences, Kumamoto University, 5-1 Oe-hon-machi, Kumamoto 862-0973, Japan

Abstract

4-Dimethylaminopyridine N-oxide effectively catalyzes the, thione to thiol rearrangement of O,S-dialkyl dithiocarbonates (xanthates) to provide S,S-diaikyl dithiocarbonates.

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Communication | Regular issue | Vol 27, No. 10, 1988, pp.2331-2332
Published online:
DOI: 10.3987/COM-88-4666
The Structure of Subulacine-N-oxide

Tammo Winkler* and Roland Heckendorn

*CIBA-GEIGY AG, CH-4002 Basel, Switzerland

Abstract

The nmr spectra reported for subulacine-N-oxide are shown to be those of 1β,2β-epoxy-1α-hydroxymethyl-8α-pyrrolizidine.

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Communication | Regular issue | Vol 27, No. 10, 1988, pp.2333-2340
Published online:
DOI: 10.3987/COM-88-4677
Guanidolide A, a Novel Antibiotic Produced by Streptomyces hygroscopicus var. Crystallogenes, the Copiamycin Source

Toshio Fukai, Chika Takahashi, Taro Nomura,* Jun Uno, and Tadashi Arai

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

Abstract

A new antibiotic, guanidolide A (2) was isolated, as well as demalonylmethylcopiamycin (1), from the mycelial cake of Streptomyces hygroscopicus var. crystallogenes. The structure of the compound (2) was determined by spectroscopic evidence.

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Communication | Regular issue | Vol 27, No. 10, 1988, pp.2341-2344
Published online:
DOI: 10.3987/COM-88-4680
Regioselectivity in the Vilsmeier-Haack Reaction of N-Benzyl-1,2,3,4-tetrahydrocarbazole

Yasuoki Murakami,* Yuusaku Yokoyama, Tomoko Miura, Sumiko Nozawa, Emiko Takeda, and Hideharu Suzuki

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

Abstract

The Vilsmeier-Haack reaction of N-benzyl-1,2,3,4-tetrahydrocarbazole (1) with various N,N-disubstituted formamides (6) and phosphorous oxychloride took place not only on the alicyclic portion but also on the benzene moiety depending on the reactivity and bulkiness of the reagents. It was also shown that N-methylformanilide (6e) is the most reactive reagent among 6.

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Communication | Regular issue | Vol 27, No. 10, 1988, pp.2345-2348
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DOI: 10.3987/COM-88-4682
Nitoroolefins. I. A New and Convenient Access to Indolizines and Pyrazolo[1,5-a]pyridines Using 1-Nitro-2-(phenylthio)ethylene

Yoshinori Tominaga,* Yuichi Ichihara, and Akira Hosomi*

*Center of Instrumental Analysis, Nagasaki University, 1-14, Bunkyo-machi, Nagasaki 852-8521, Japan

Abstract

1-Nitro-2-(phenylthio)ethylene (1) reacts with a variety of N-ylides and N-imines (pyridinium, isoquinolinium, quinolinium, phthalazinium N-ylides and N-imines) in the presence of triethylamine to give the corresponding fused pyrrole and pyrazole derivatives (indolizines, pyrrolo[2,1-a]isoquinoline, pyrrolo[2,1-a]phthalazine, pyrazolo[1,5-a]-pyridine, pyrazolo[5,1-a]quinoline, and pyrazolo[5,1-a]isoquinoline) along with the corresponding l-nitropyrrolopyridines and 1-nitropyrazolopyridines, respectively, in moderate yields.

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Communication | Regular issue | Vol 27, No. 10, 1988, pp.2349-2352
Published online:
DOI: 10.3987/COM-88-4692
Synthesis of α,β-Unsaturate γ-Butyrolactams by Knoevenagel Condensation

Masazumi Ikeda,* Takamasa Uchino, Kazumi Matuyama, and Ayami Sato

*Kyoto Pharmaceutical University, Misasagi-Shichonocho, Yamashina, Kyoto 607-8414, Japan

Abstract

When 2-alkylaminocyclohex-2-enones 1a-d were allowed to react with ethyl chloroformylacetate in the presence of pyridine and 4-(dimethylamino) pyridine. the carbamoylacetates 2a-d and the 2H-indol-2-ones 3a-d were obtained. Upon treating with ammonium acetate, 2a-d were converted into 3a-d. Reaction of 1a and 1c with cyanoacetyl chloxide gave only the 1H-indol-2-ones 6a,c. This reaction was extended to ttle synthesis of the erythrinan skeleton.

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Communication | Regular issue | Vol 27, No. 10, 1988, pp.2353-2362
Published online:
DOI: 10.3987/COM-88-4711
New Regio- and Stereocontrolles Reactions of 2-Vinylindoles with CC-Dienophiles: Diels-Alder Reactions, Ene Reactions and Michael Additions

Manfred Eitel and Ulf Pindur*

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

Abstract

The reactions of selectively functionalized 2-vinylindoles with some acyclic and cyclic CC-dienophiles yield Diels-Alder adducts, Diels-Alder ene products, and Michael adducts, respectively, with very high regio- and/or stereoselectivities. This methodology provides a convenient access to functionalized indoles, carbazoles, and [c]pyrroloannellated carbazoles with substitution patterns that are not so easily accessible by other routes.

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Communication | Regular issue | Vol 27, No. 10, 1988, pp.2363-2365
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DOI: 10.3987/COM-88-4717
A Simple Synthesis of 7-Substituted 1-Acethy-2,3-dihydroindoles

Masanori Somei,* Toshiya Kawasaki, and Toshiharu Ohta

*Faculty of Pharmaceutical Sciences, Kanazawa University, 13-1 Takara-machi, Kanazawa 920-0934, Japan

Abstract

7-Cyano-, 7-hydroxy-, 7-methoxycarbonyl-, 7-methyl-, 7-nitro-, and 7-phenyl-1-acetyl-2,3-dihydroindoles are prepared in two steps (or one pot) from 1-acetyl-2,3-dihydroindole.

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Paper | Regular issue | Vol 27, No. 10, 1988, pp.2367-2372
Published online:
DOI: 10.3987/COM-88-4593
Synthesis of Norsecocularines

Emilia Tojo, Domingo Domínguez, and Luis Castedo*

*Facultad de Química y Sección de Alcaloides, Deparamento de Química Orgánica, C. S. I. C., Santiago de Compostela, Spain

Abstract

The transformation of cularines into N-norsecocularine alkaloids using a Cope elimination to cleave the nitrogenated ring is reported.

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Paper | Regular issue | Vol 27, No. 10, 1988, pp.2373-2379
Published online:
DOI: 10.3987/COM-88-4617
Synthesis of Some 6-Arylamino-3-amino-1,2,4,5-dithiadiazines

Anirudh P. Singh, Rajendra Singh, and Vinay Kumar Verma*

*Department of Applied Chemistry, Institute of Technology, Banaras Hindu University, Varanasi-221 005, India

Abstract

The synthesis of some new 6-arylamino-3-amino-1,2,4,5-dithiadiaztaes (IIIa-e) has been achieved by following a novel route.

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Paper | Regular issue | Vol 27, No. 10, 1988, pp.2381-2386
Published online:
DOI: 10.3987/COM-88-4620
Biomimetic Transformation of Hodgkinsine, a Pyrrolidinoindoline Alkaloid

Francine Libot, Nicole Kunesch,* Jacques Poisson, Manfred Kaiser, and Helmut Duddeck

*Laboratorie de Chimie des Substances Thérapeutiques Naturelles, Centre d’Etudes Pharmaceutiques, 92296 Châtenay-Malabry Cedex, France

Abstract

The transformation of hcdgkinsine 1 under mild acidic conditions provides a new compound whose structure has been shown to possess calycanthine and pyrrolidinoindoline subunits. This compound could be identified with calycosidine 2 previously isolated from Calycodendron milnei. General implications of this reaction are discussed.

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Paper | Regular issue | Vol 27, No. 10, 1988, pp.2387-2393
Published online:
DOI: 10.3987/COM-88-4637
New Alkaloids from Delphinium andersonii Gray

S. William Pelletier,* A. Mukendi Panu, Palaniaooan Kulanthaivel, and John P. Olsen

*Department of Chemistry, Institute for Natural Products Research, The University of Georgia, Chemistry Building, Athens, Georgia 30602-2556, U.S.A.

Abstract

Andersonine (1) and 14-deacetylnudicauline (2), two new C19-diterpenoid alkaloids, have been isolated from Delphinium andersonii Gray. Structures were deduced by spectroscopic methods. The structures of andersonine and 14-deacetylnudicauline were confirmed by correlation with nudicauline (5). Six known alkaloids were also isolated: delavaine (3), delectinine (8) lycoctonine (7), methyllycaconitine (6), nudicauline (5), and takaosamine (4).

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Paper | Regular issue | Vol 27, No. 10, 1988, pp.2395-2402
Published online:
DOI: 10.3987/COM-88-4641
Autoxidation of Lithio Derivative of 2-Isoxazolines

Sergio Auricchio* and Aldo Ricca

*Dipartimento di Chimica, Politecnico di Milano, Piazza Leonardo da Vinci 32, 20133 Milano, Italy

Abstract

4-Lithio-2-isoxazolines are oxidized to the 4-peroxides or 4-hydroxy derivatives by air or oxygen at -80 °C. The concentration of oxygen in the solution is a decisive parameter. When it is bubbled into the lithium salt solution, the 4-hydroperoxide derivatives are mainly formed. However if oxygen is slowly absorbed in the liquid phase, 4-hydroxy derivatives predominate. In the reaction, the hydroperoxide anions has been confirmed to be the precursors of the 4-hydroxy-2-isoxazolines.

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Paper | Regular issue | Vol 27, No. 10, 1988, pp.2403-2412
Published online:
DOI: 10.3987/COM-88-4647
Studies on Friedel-crafts Acylation of N-Acetylhompveratrylamine and Preparation of 1-Substituted 3,4-Dihydro-6,7-dimethoxyisoquinolines

Kazuhiko Orito,* Tsutomu Matsuzaki, Hiroshi Suginome, and Russel Rodrigo

*Division of Molecular Chemistry, Graduate School of Engineering, Hokkaido University, Kita 13 Nishi 8, Kita-ku, Sapporo, Hokkaido 060-0828, Japan

Abstract

Friedel-Crafts acylation of N-acetylhomoveratrylamine in a molar ratio of 1:2:3 of 1, AlCl3 and the appropriate acid chloride using nitrobenzene as solvent gave the corresponding 2-acyl derivatives 2a-j in good yields. Subsequent treatment of 2 in boiling 1N-hydrochloric acid afforded a variety of 1-substituted 3,4-dihydro-6,7-dimethoxyisoquinolines 3a-j in almost quantitative yields. The dihydroisoquinolines-3h-j having carboxyalkyl groups at C1-position were further converted to the benzo[a]quinolizine analogues 6a-j.

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Paper | Regular issue | Vol 27, No. 10, 1988, pp.2413-2415
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DOI: 10.3987/COM-88-4648
Conversion of 2,3-O-Cyclohexylidene-(D)-ribonolactone into 2,3-O-Cyclohexylidene-(L)-ribonolactone

Seiichi Takano,* Kohei Inomata, and Kunio Ogasawara

*Pharmaceutical Institute, Tohoku University, Aobayama, Sendai 980-8578, Japan

Abstract

A convenient method forthe chirality inversion of 2,3-O-cyclohexylidene-D-rlbonolactone to 2,3-O-cyclohexylidene-L-ribonolactone has been established.

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Paper | Regular issue | Vol 27, No. 10, 1988, pp.2417-2422
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DOI: 10.3987/COM-88-4649
Photochemistry of the N-Acyllactam and Acyclic Thioimide Systems. Competition between Paterno-Büchi Type and Norrish Type 1 Reactions

Kazuaki Oda,* Minoru Machida, and Yuichi Kanaoka

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

Abstract

Irradiation of semlcyclic- (4) and acyclic thioimides (9) gave thietanes (6, 7, and 10) and/or α-cleavaged products (8 and 11), formations of those were explained in terms of Paterno-BÜchi type and Norrish type I processes.

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Paper | Regular issue | Vol 27, No. 10, 1988, pp.2423-2429
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DOI: 10.3987/COM-88-4659
Structure and Synthesis of Cucumopine, a New Crown Gall and Hairy-root Opine

Elisabeth Davioud, Jean-Charles Quirion, Max E. Tate, Jacques Tempé, and Henri-Philippe Husson*

*Institut des Chimie des Substances Naturelles, C.N.R.S., 1 avenue de la Terrasse, Bat. 27, 91198 Gif-sur-Yvette Cedex, France

Abstract

The opine known as cucumopine 1 produced by crown gall tumours and hairyroot exhibited chemical and spectroscopic data corresponding to 4-(2-carboxyethy1)-4,5,6,7-tetrahydroimidazo[4,5-c]pyridine-4,6-dicarboxylic acid. The identification was verified by a biogenetic type synthesis from L-histidine and α-ketoglutaric acid.

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Paper | Regular issue | Vol 27, No. 10, 1988, pp.2431-2438
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DOI: 10.3987/COM-88-4661
Reactivity of Isoselenazole Derivatives towards Electrophilic Reagents

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

The behaviour of isoselenazoles towards electrophilic reagents including reversible protonation at the nitrogen atom, hydrogen-deuterium exchange, bromination and nitration is explored. Electrophilic substitutions take place only in the 4 position.

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Paper | Regular issue | Vol 27, No. 10, 1988, pp.2439-2441
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DOI: 10.3987/COM-88-4669
Reaction of 6-Glycosylaminopyrimidin-4-ones with Diethyl Ethoxymethylenemalonate in Acidic Medium

José A. García, Adolfo Sánchez, and Manuel Nogueras

*Dept. Química Orgánica, Colegio Universitario de Jaén, Universidad de Granada, 23071 Jaén, Spain

Abstract

Starting from the already known 6-glycopyranosylaminopyrimidin-4-ones, some novel (E)-5-(2-carbethoxyvinyl) derivatives have been synthesized by the reaction with diethyl ethoxymethylenemalonate (EMME) in acetic acid.

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Paper | Regular issue | Vol 27, No. 10, 1988, pp.2443-2457
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DOI: 10.3987/COM-88-4681
Pyrazoles 3. N-1 Protected 4-Substituted Pyrazoles — Synthesis and Nmr Investigation

Gottfried Heinisch and Wolfgang Holzer*

*Institute of Pharmaceutical Chemistry, University of Vienna, Währinger Strasse 10, A-1090 Vienna, Austria

Abstract

13C-Nmr Data (chemical shifts, substituent chemical shifts (SCS), coupling constants) are reported for 26 1,4-disubstituted pyrazoles, bearing a benzyl, benzoyl or (substituted) benzenesulfonyl protecting group at N-1. The pyrazole derivatives 8a-d were prepared from the corresponding NH-pyrazoles. In the synthesis of compounds 2-5 l-benzyl-4-pyrazolecarbaldehyde served as the starting material.

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Paper | Regular issue | Vol 27, No. 10, 1988, pp.2459-2465
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DOI: 10.3987/COM-88-4687
Improved Preparation of Precocene II. Unexpected Results in the Reduction of Alkoxy Substituted Acetophenones and 4-Chromanones with Sodium Borohydride

Pilar Teixidor, Francisco Camps, and Angel Messeguer*

*Departmenr of Biological Chemistry, C.I.D. (CSIC), J. Giroba 18. 08034-Barcelona, Spain

Abstract

An improved preparation of natural pro-allatocidin precocene II (6) is reported. Starting from methoxyhydroquinone (1). Fries condensation with acid 2 led to the hydroxychromanone 2, which by further methylation, reduction and dehydration afforded chromene 6 in 77% overall yield. In addition, complementary studies related to the synthetic sequence have also been carried out, i.e., the influence of water contents on the initial Fries rearrangement and the scope of an anomalous reaction course in the reduction of aromatic ketones with NaBH4/MeOH in which, depending upon the activation of the carbonyl group, the formation of the methyl ether instead of that of the corresponding alcohol might be observed.

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Paper | Regular issue | Vol 27, No. 10, 1988, pp.2467-2473
Published online:
DOI: 10.3987/COM-88-4698
Delstaphigine and 14-O-Benzoyldelphonine, New Alkaloids from Delphinium staphisagria Linne‘

S. William Pelletier,* Samir A. Ross, and Jpseph T. Etse

*Department of Chemistry, Institute for Natural Products Research, The University of Georgia, Chemistry Building, Athens, Georgia 30602-2556, U.S.A.

Abstract

Delstaphigine (1) and 14-O-benzoyldelphonine (2), two new C19-diterpenoid alkaloids, and chasmaconitine (4) have been isolated from the seeds of Delphinium staphisagria. The structures of these alkaloids were determined from spectral data and by correlation with alkaloids of established structures. Thus methylation of delstaphigine (1) afforded delphinine (3). 14-O-Benzoyldelphonine (2) was synthesized from both delphinine (3) and delphonine (5). Chasmaconitine (4) has not been previously isolated from a Delphinium species.

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Paper | Regular issue | Vol 27, No. 10, 1988, pp.2475-2479
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DOI: 10.3987/COM-88-4704
Synthesis of 5-Alkylpyrrolizin-3-ones from the Lukes-Sorm Lactam by Grignard Reaction and Recyclization of Intermadiate 5-Bromoalkylpyrrolidin-2-ones

Kimio Takahashi and Arnold Brossi*

*Section of Medical Chemistry, Laboratory of Analytical Chemistry, NIDDK, National Institute of Health, Bethesda, MD 20982, U.S.A.

Abstract

Synthesis of 5-alkylpyrrolizidin-3-ones 2 and 8 from pyrrolizidin-3,5-dione 1 is described. Grignard reaction of 1 gave 5-(3’-oxobutyl)pyrroiidin-2-one 2. Reduction of 2 with sodium borohydride, followed by mesylation, bromination, and cyclization afforded a diastereomeric mixture 7a and 8a, which were separated by chromatography. The same procedure with 3, also obtained from 1 by a Grignard reaction, afforded 7b and 8b.

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31 data found. 1 - 30 listed Next Last