Regular Issue

Vol. 36, No. 7, 1993

24 data found. 1 - 24 listed
Communication | Regular issue | Vol 36, No. 7, 1993, pp.1455-1458
Published online:
DOI: 10.3987/COM-92-6245
Lamarckinine, a New Bisnorditerpenoid Alkaloid from Aconitum lamarckii Reichenb.

Gabriel de la Fuente,* Tomás Orribo, José A. Gavín, and Rafael D. Acosta

*Instituto de Productos Naturales y Agrobiologia de Canrias, CPNO "Antonio Gonz!aez", C. S. I. C./ Unversidad de La Laguna, P.O. Box 195, 38206- La Laguna, Tenerife, Spain

Abstract

A new bisnorditerpenoid alkaloid lamarckinine (1) containing a C(19) = N- azomethine group was isolated from Aconitum lamarckii Reichenb., besides neoline, 1,14-diacetylneoline, 8-O-ethylbenzoylaconine, columbianine, delcosine, lycoctonine, and 18-methoxygadesine. The structure of the new alkaloid was elucidated by 2D nmr spectroscopy and its conversion into deoxymethylenelycoctonine.

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Communication | Regular issue | Vol 36, No. 7, 1993, pp.1459-1462
Published online:
DOI: 10.3987/COM-93-6354
Novel Condensation Reactions of N-Cycloheptatrienylidene Alkylamine N-Oxides with Acetylene Derivatives: Facile Formation of 1-Azaazulen-2(1H)-ones

Kazuaki Ito, Katsuhiro Saito,* and Kensuke Takahashi

*Department of Applied Chemistry, Nagoya Institute of Technology, Gokiso-cho, Showa-ku, Nagoya 466-8555, Japan

Abstract

Reactions of N-cycloheptatrienylidene alkylamine N-oxide with acetylene derivatives having electron attracting group afforded 1-azaazulen-2(1H)-one derivatives through a unique condensation process leaving methyl formate or hydrogen.

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Communication | Regular issue | Vol 36, No. 7, 1993, pp.1463-1469
Published online:
DOI: 10.3987/COM-93-6357
Pd(0)-Catalysed Synthesis of Buspirone and Gepirone

David L. Kuo

*Research and Development Department, Lonza Ltd., Walliser Werke, CH-3930 Visp, Switzerland

Abstract

A novel synthetic approach to buspirone and its anologue (gepirone) is described, in which 3 subunits, namely 2-(1-piperazinyl)pyrimidine, a bifunctional allylderivative, and an imide were efficiently assembled via a Pd(0)-catalysed amination-imidation sequence followed by a hydrogenation.

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Communication | Regular issue | Vol 36, No. 7, 1993, pp.1471-1476
Published online:
DOI: 10.3987/COM-93-6361
Synthesis of Some 5,6-Dihydro-7H-1,4,2-oxathiazepin-7-ones and 5H-4,1,3-Benzoxathiazepin-5-ones

Wynona Johnson, Stuart Littler, and Colin Skene*

*CSIRO, Division of Chemicals and Polymers, Praivate Bag 10, Clayton, South MDC, Victoria, 3168, Australia

Abstract

The novel heterocyclic systems 5,6-dihydro-7H-1,4,2-oxathiazepin-7-one (1) and 5H-4,1,3-benzoxathiazepin-5-one (2) were prepared by the reaction of hydroximoyl chlorides (3) with mercapto-carboxylic acids, followed by cyclization with 1,3-dicyclohexylcarbodiimide (6) or 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide HCl (7).

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Communication | Regular issue | Vol 36, No. 7, 1993, pp.1477-1481
Published online:
DOI: 10.3987/COM-93-6365
Photochemical Reaction of 6-Alkoxy-7-(2-oxoalkyl)quinoline-5,8-quinones

Katsuhiko Nakagawa,* Hirofumi Kaneko, Takashi Yano, Shigehiro Inai, Kenzo Tabuchi, and Shozo Shimada

*Department of Industrial Chemistry, Niihama National College of Technology,7-1 Yagumo-machi, Niihama, Ehimie 792, Japan

Abstract

Photochemical reaction of 6-alkoxy-7-(2-oxoalkyl)quinoline-5,8-quinones in benzene gave a novel heterocyclic quinones, 2-aklyl-4-methylquino[6,7-d][1,3]dioxepine-6,11-diones via intramolecular γ-H-abstraction.

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Communication | Regular issue | Vol 36, No. 7, 1993, pp.1483-1488
Published online:
DOI: 10.3987/COM-93-6368
A Regiospecific Synthesis of Carbazoles via Consecutive Palladium-catalyzed Cross-Coupling and Aryne-mediated Cyclization

Masatomo Iwao,* Hirokazu Takehara, Sunao Furukawa, and Mitsuaki Watanabe*

*Faculty of Liberal Arts, Nagasaki University, 1-14, Bunkyo-machi, Nagasaki 852-8521, Japan

Abstract

A regiospecific synthesis of carbazoles has been developed using palladium-catalyzed cross-coupling of N-(tert-butoxycarbonyl)-2-tributylstannylanilines with 2- or 3-bromochlorobenzene followed by aryne-mediated cyclization as the key reactions. The carbazole alkaloids, glycozolinine and glycozolidine, were synthesized using this procedure.

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Communication | Regular issue | Vol 36, No. 7, 1993, pp.1489-1492
Published online:
DOI: 10.3987/COM-93-6374
Synthesis of (-)-Nonactic Acid: Application of γ-Dithio-β-hydroxy Ester Prepared by Microbial Reduction as a Chiral Building Block

Kazuhiko Takatori, Nobuyuki Tanaka, Kenji Tanaka, and Masahiro Kajiwara*

*Department of Medicinal Chemistry, Meiji College of Pharmacy, 1-22-1 Yato-cho, Tanashi-shi, Tokyo 188, Japan

Abstract

A γ-dithio-β-hydroxy ester (2), prepared by microbial reduction with baker’s yeast, was used as a chiral building block, for the synthesis of (-)-nonactic acid (1). It was converted to the lithium acetylide via 5, of which 1,2-addition to the aldehyde (6) followed by reduction gave the 3-silyloxy-6-tosyloxynonane (8b). On cleavage of the silyl ether, cyclization proceeded with complete inversion of configuration at C-6 to afford a cis-2,5-disubstituted tetrahydrofuran (9), which was led to 1.

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Communication | Regular issue | Vol 36, No. 7, 1993, pp.1493-1496
Published online:
DOI: 10.3987/COM-93-6377
A New Potential Acyl Iminium Ion for the Asymmetric Synthesis of Piperidine Derivatives

Jacques Royer 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

Epimeric oxazolopiperidones (1a) and (1b) were prepared independently, both from R-(-)-phenylglycinol as starting material. They represent chiral potential iminium ions.

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Communication | Regular issue | Vol 36, No. 7, 1993, pp.1497-1500
Published online:
DOI: 10.3987/COM-93-6383
Reaction of 2-Trimethylsilylmethylthiopyridine Promoted by a Fluoride Ion: The First Example of Generation of 2-Pyridylthiomethylcarbanion

Shinya Kohra,* Hiroshi Ueda, and Yoshinori Tominaga

*Faculty of Liberal Arts, Nagasaki University, 1-14, Bunkyo-machi, Nagasaki 852-8521, Japan

Abstract

2-Trimethylsilylmethylthiopyridine prepared readily by the reaction of 2-mercaptopyridine with chloromethyltrimethylsilane in the presence of potassium carbonate reacts with carbonyl compounds in the presence of a catalytic amount of tetrabutylammonium fluoride (TBAF) to give 2-(2-pyridylthio)ethanols. This reaction is the first example of generation and introduction of 2-pyridylthiomethylcarbanion.

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Paper | Regular issue | Vol 36, No. 7, 1993, pp.1501-1507
Published online:
DOI: 10.3987/COM-92-6288
Two New Coumaronochromone Derivatives, Oblongin and Oblonginol from the Roots of Derris oblonga Benth

Yun-Lian Lin and Yueh-Hsiung Kuo*

*Department of Chemistry, National Taiwan University, Roosevelt Road Section 4, Taipei 106, Taiwan, R.O.C.

Abstract

Two new coumaronochromone derivatives, oblongin and oblonginol, have been isolated from the roots of Derris oblonga. Their structures have been elucidated by spectroscopic and chemical methods.

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Paper | Regular issue | Vol 36, No. 7, 1993, pp.1509-1519
Published online:
DOI: 10.3987/COM-92-6305
Synthesis of N-Demethyl-N-substituted 14β-Hydroxy isomorphine and Dihydroisomorphine Derivatives

Sándor Hosztafi, Csaba Simon, and Sándor Makleit*

*Department of Organic Chemistry, Lajos Kossuth University, P.O.Box 20, H-4010 Debrecen, Hungary

Abstract

Some new representatives (3e-3h, 5g) of a new group of structurally related morphine-agonist and antagonist compounds have been prepared in stereochemically homogeneous forms. Application of the Mitsunobu-reaction for suitable codeine derivatives (1a-1d) gave the benzoates (2a-2d) of the hitherto unknown C-6 iso-compounds, which were converted into the desired isocodeines (3b-3d) by means of alkaline hydrolysis. O-Demethylation of these derivatives afforded the corresponding morphine analogues. The preparation of 3e was also carried out from 1f via compound (2e). A hitherto unknown N-demethylation also allowed the conversion of 3a and 5a into the target compounds. With the exception of N-allyl derivatives, the dihydro analogues were obtained by the hydrogenation of the C7-C8 double bond.

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Paper | Regular issue | Vol 36, No. 7, 1993, pp.1521-1528
Published online:
DOI: 10.3987/COM-92-6318
A Simple Method for Synthesis of 4-Dimethylamino-2,6-dimethyl-5-phenylpyrimidines

Wojciech Zielinski* and Monika Mazik

*Instiute of Organic Chemistry and Technology, Silesian University of Technology, ul. Krzywoustego 4, 44-101 Gliwice, Poland

Abstract

The reaction of N-(1-methyl-2-phenylvinyl)acetimidoyl chloride and its derivatives substituted at the benzene ring with N,N-dimethylcyanamide was studied. At the first stage, linear products like 1-chloro-1-dimethylamino-3,5-dimethyl-6-phenyl-2,4-diaza-1,3,5-hexatrienes were obtained. They underwent cyclization to 4-dimethylamino-2,6-dimethyl-5-phenylpyrimidines in alkaline medium at elevated temperature.

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Paper | Regular issue | Vol 36, No. 7, 1993, pp.1529-1539
Published online:
DOI: 10.3987/COM-92-6326
Synthesis of Penams from 1H-Azetidinones by Intramolecular Carbenoid Insertion

Pierluigi Bissolino, Marco Alpegiani, Daniela Borghi, Ettore Perrone, and Giovanni Franceschi*

*Farmitalia Carlo Erba R&D, Via C.Imbonati 29, 20146 Milano, Italy

Abstract

Construction of the penam ring system has been achieved by dirhodium tetraacetate cyclization of 4-thio-1H-azetidinone derivatives bearing an α-diazoester appendage. The sulfur atom of 4-thioethers interferes by reacting with the electrophilic metal carbene, but the corresponding sulfone and sulfoxides undergo the prescribed cyclization exclusively. Nmr studies on obtained bisnorpenams indicate pseudoequatorial puckering for the thiazolidine ring of the S-sulfoxide, while the parent sulfide and the R-sulfoxide exist as pseudoaxial conformers.

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Paper | Regular issue | Vol 36, No. 7, 1993, pp.1541-1551
Published online:
DOI: 10.3987/COM-92-6329
SRN1 Reactions in Imidazo[1,2-a][1,8]naphthyridine Series

Patrice Vanelle,* Saïd Ghezali, José Maldonado, Olivier Chavignon, Alain Gueiffier, Jean-Claude Teulade, and Michel P. Crozet*

*Radicaux Libres et Synthèse, CNRS URA 1412, Université e’Aix-Marseille III, Faculté des Sciences et Techniques de St.-Jérôme, Avenue Escardrille Normandie-Niemen BP 562,13397 Marseille Cedex 20, France

Abstract

8-Chloromethyl-2,4-dimethyl-9-nitroimidazo[1,2-a][1,8]naphthyridine was synthesized as reductive alkylating agent and its reactivity with 2-nitropropane anion was investigated. The SRN1 mechanism of the C-alkylation was confirmed by the inhibitory effects of p-dinitrobenzene, molecular oxygen and TEMPO. Extension of this SRN1 reaction to various nitronate anions leads after nitrous acid elimination to a new class of imidazo[1,2-a][1,8]naphthyridine derivatives bearing a trisubstituted double bond at the 8 position.

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Paper | Regular issue | Vol 36, No. 7, 1993, pp.1553-1560
Published online:
DOI: 10.3987/COM-93-6337
Studies on Quinones. Part 26. The Reaction of Methacrolein N,N-Dimethylhydrazone with Activated Benzoquinones

Jaime A. Valderrama* and M. Florencia González

*Facultad de Química, Pontificia Universidad Católica de Chile, Casilla 306, Correo 22, Santiago, Chile

Abstract

A one-step formation of 5-hydroxy-2,3-dihydrobenzo[b]furans by a [3+2] addition process of methacrolein N,N-dimethylhydrazone (4) with a variety of 1,4-benzoquinones bearing activating groups is reported.

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Paper | Regular issue | Vol 36, No. 7, 1993, pp.1561-1575
Published online:
DOI: 10.3987/COM-93-6339
The Chemistry of Polyphyrins 2. Syntheses of Hexaphyrins and Their Metal Complexes

Roland Charriere, Titus A. Jenny, Hans Rexhausen, and Albert Gossauer*

*Institut für Organische Chemie, Universität Freiburg I. Ue., ret. du Musée, CH-1700 Fribourg, Switzerland

Abstract

The synthesis of eight derivatives of a 26 π-electron macrocycle analogous to the porphyrins bearing six pyrrole rings and six methine bridges is described. This chromophore is named hexaphyrin. Owing to the flexibility of their chromophore, hexaphyrins are able to form two kind of binuclear coordination complexes of substantially different geometry.

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Paper | Regular issue | Vol 36, No. 7, 1993, pp.1577-1588
Published online:
DOI: 10.3987/COM-93-6350
Rearrangement of 3-(N-Heteroarylamino)-1,2,5-oxadiazoles: Triazolo[1,5-a]quinolines and Triazolo[1,5-a]pyridines

Giuseppe Cusmano,*Gabriella Macaluso, and Michelangelo Gruttadauria

*Dipartimento di Chimica Organica, Università digli Studi di Palermo, Via Archirafi 20 90123 Palermo, Italy

Abstract

The rearrangement reaction of 1,2,5-oxadiazole derivatives bearing quinoline and pyridine heterocycles in a N-C-N side chain sequence was investigated. Triazolo[1,5-a]quinoline and triazolo[1,5-a]pyridine oximes were obtained in good yield.

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Paper | Regular issue | Vol 36, No. 7, 1993, pp.1589-1599
Published online:
DOI: 10.3987/COM-93-6353
A New Synthetic Route to the Previously Unattainable 3-Substituted 2,3-Dihydro-1,4-dioxino[2,3-b]pyridines

Abdelhakim Benarab, Pascal Poirot, and Gerald Guillaumet*

*Laboratoire de Chimie Bioorganique et Analytique, URA-CNRS N° 499, Université d’Orléans, BP 6759, Rue de Chartres, 45067 Orleans Cedex 2, France

Abstract

A variety of 3-substituted-2,3-dihydro-1,4-dioxino[2,3-b]pyridines (3) have been synthesized from the readily available 2-chloro-3-oxiranylmethoxypyridine (1). Treatment of this epoxide by various nucleophile reagents provided alcohols (2a-i) which, by displacement of the chlorine, gave the desired products (3a-i) in satisfactory yields.

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Paper | Regular issue | Vol 36, No. 7, 1993, pp.1601-1616
Published online:
DOI: 10.3987/COM-93-6367
Synthesis of Thioaldehydes Having Optically Active Alkoxy Moiety and Their Asymmetric Hetero Diels-Alder Reaction

Tamiko Takahashi, Noriyuki Kurose, Toru Koizumi,* and Motoo Shiro*

*Faculty of Pharmaceutical Sciences, Toyama Medical and Pharmaceutical University, 2630 Sugitani, Toyama, Toyama 930-0194, Japan

Abstract

Optically active α-alkoxycarbonylthioaldehydes (2a-g) were prepared using 8-arylmethols as chiral auxiliaries. Their asymmetric hetero Diels-Alder reactions with cyclopentadiene gave the endo cycloadducts (3 and 4) and exo cycloadducts (5 and 6) with moderate diastereomeric excesses. However, the major endo cycloadducts (3b-g) were isolated in optically pure form. This is the first chiral synthesis of 2-thiabicyclo[2.2.1]hept-5-ene ring system. The absolute configuration of the cyclic carbonate (12), which was prepared from the major endo cycloadduct (3c) via the epimerization, or the minor exo compound (6c), was determined as 1R by X-ray analysis. The cycloadduct (3c) was transformed to a potential intermediate (14) for the synthesis of carbocyclic homonucleosides.

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Paper | Regular issue | Vol 36, No. 7, 1993, pp.1617-1623
Published online:
DOI: 10.3987/COM-93-6370
C-Nucleosides. 21. Synthesis of Isoxazole C-Nucleoside from Furanone Glycoside via Enaminone Glycoside

Isamu Maeba,* Yasutaka Ito, Masakazu Wakimura, and Chihiro Ito

*Faculty of Pharmacy, Meijo University, 150 Yagotoyama, Tenpaku, Nagoya 468-8503, Japan

Abstract

Synthesis of the versatile and stable C-nucleoside precursor enaminone glycosides (3a,b) was achieved by reaction of furanone glycoside (1) with 2- and 4-aminophenols. Treatment of enaminone (3b) with hydroxylamine hydrochloride yielded 5-hydroxy-4,5-dihydroisoxazole (5), which on dehydration with toluene-p-sulfonic acid in benzene gave 5-(2,3,5-tri-O-benzoyl-β-D-ribofuranosyl)isoxazole (6). Deblocking of compound (6) with sodium carbonate gave 5-(β-D-ribofuranosyl)isoxazole (7).

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Paper | Regular issue | Vol 36, No. 7, 1993, pp.1625-1630
Published online:
DOI: 10.3987/COM-93-6371
The Alkylation of 2-Amino-6-chloropurine with Alcohols by Mitsunobu Reaction for a Synthesis of Carbocyclic Guanosine Analogs

Akemi Toyota,* Nobuya Katagiri, and Chikara Kaneko

*Phamaceutical Institute, Tohoku University, Aramaki, Aoba-ku, sendai 980-8578, Japan

Abstract

Mitsunobu reaction of 2-amino-6-chloropurine with various alcohols which provides a convenient method for a synthesis of carbocyclic or acyclic guanosine analogs is described.

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Paper | Regular issue | Vol 36, No. 7, 1993, pp.1631-1639
Published online:
DOI: 10.3987/COM-93-6375
Synthesis of Novel, Fused Benzoxazocines by an Unexpected Intramolecular Cyclisation

William J. Coates and Dashyant Dhanak*

*SmithKline Beecham Pharmacuticals, The Frythe, Welwyn, Hertfordshire, AL6 9AR, U.K.

Abstract

Novel, fused benzoxazocines are obtained from the treatment of 2-(2-(3-hydroxypropoxy)phenyl)benzimidazole and imidazopyridine derivatives with trifluoroacetic anhydride followed by heating in HMPA.

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Paper | Regular issue | Vol 36, No. 7, 1993, pp.1641-1644
Published online:
DOI: 10.3987/COM-93-6379
A One-Step Synthesis of 2,3-Diydro-1,4-benzothiazines and Phenothiazines from 1,3-Thiazolidine Derivatives of Cyclohexanones

Romualdo Caputo, Carla Ferreri,* Luigi Longobardo, Domenico Mastroianni, Giovanni Palumbo,* and Silvana Pedatella

*Dipartimento di Chimica Organica e Biologica, Università di Napoli "Federico II", Via Mezzocannone 16, I-80134 Napoli, Italy

Abstract

N-Acetyl-1,3-thiazolidine derivatives of cyclohexanones, when treated with a threefold excess N-bromosuccinimide in anhydrous chloroform at room temperature, smoothly afford N-acetyl-2,3-dihydro-1,4-benzothiazines. This represents the first general route to such heterocyclic system in one step from aliphatic precursors. The synthesis of optically active N-acetyl-2,3-dihydro-1,4-benzothiazines is also reported.

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Review | Regular issue | Vol 36, No. 7, 1993, pp.1645-1678
Published online:
DOI: 10.3987/REV-92-452
Host-Guest Complexes of Azaaromatic Quaternary Salts

Wanda Sliwa,* Lidia Chrzastek, and Marian Mielniczak

*Institute of Chemistry, Pedagogical University, 25-020 Kielce, Poland

Abstract

Inclusion complexes, where azaaromatic quaternary salts serve as a guest or as a host are described, along with related rotaxanes and catenanes.

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24 data found. 1 - 24 listed