Regular Issue

Vol. 34, No. 7, 1992

20 data found. 1 - 20 listed
Communication | Regular issue | Vol 34, No. 7, 1992, pp.1277-1280
Published online:
DOI: 10.3987/COM-92-6065
Isolation of Acromelic Acids D and E from Clitocybe acromelalga

Shinji Fushiya, Seiichi Sato, Yasuko Kera, and Shigeo Nozoe*

*Pharmaceutical Institute, Tohoku University, Aobayama, Aoba-ku, Sendai 980, Japan

Abstract

Two analogs of acromelic acid were isolated from Clitocybe acromelalga. The Structures of these compounds, acromelic acids D and E were determined to be 4 and 5, respectively by 1H nmr analysis and by comparison of the spectral data with that of the synthetic one in the case of 4.

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Communication | Regular issue | Vol 34, No. 7, 1992, pp.1281-1284
Published online:
DOI: 10.3987/COM-92-6041
Synthesis of Extended 1,3-Polyols Using Four-Carbon Units: An Approach to the Construction of the Polyol Fragment of Roxaticin

Yuji Mori,* Motoya Asai, and Hiroshi Furukawa

*Faculty of Pharmacy, Meijo University, Tempaku, Nagoya 468, Japan

Abstract

The Polyol fragment of roxaticin containing eight chiral centers has been prepared in a reiterative manner using coupling reactions of chiral dithianes with epoxides followed by stereoselective reduction.

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Communication | Regular issue | Vol 34, No. 7, 1992, pp.1285-1288
Published online:
DOI: 10.3987/COM-92-6044
A Novel Synthesis of 2,2’-Bisindole and Its Application for the Synthesis of Indolo[2,3-a]carbazole Derivatives

Masanori Somei* and Atsushi Kodama

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

Abstract

A novel oxidative coupling method of 2-lithio-1-methoxyindole was developed resulting in the formation of 2,2’-bis(1-methoxyindole) (6). Catalytic hydrogenation of 6 produced 2,2’-bisindole (9). Diels-Alder reaction of 9 with dienophiles afforded indolo[2,3-a]carbazole derivatives.

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Communication | Regular issue | Vol 34, No. 7, 1992, pp.1289-1293
Published online:
DOI: 10.3987/COM-92-6060
An Unprecedented Reaction of Diethylaminosulfur Trifluoride with Furanones

Virendra Kumar* and Malcolm R. Bell

*Sterling Winthrop Pharmaceuticals Research Division, Rensselaer, NY 12144, U.S.A.

Abstract

Reaction of diethylaminosulfur trifluoride (DAST) with furanones did not provide the expected gem-difluoro compounds instead the methylene hydrogens of furanones were replaced by a fluorine and sulfinyl group.

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Communication | Regular issue | Vol 34, No. 7, 1992, pp.1295-1298
Published online:
DOI: 10.3987/COM-92-6066
A Regioselective Lithiation of 1-Methoxymethoxyindole at the 2-Position and Its Application for the Synthesis of 2-Substituted Indoles

Masanori Somei* and Tetsuya Kobayashi

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

Abstract

A regioselective lithiation of 1-methoxymethoxyindole at the 2-position was achieved with n-BuLi at 0 °C. Subsequent treatment with electrophiles afforded 2-substituted 1-methoxymethoxyindoles, which were readily converted to 2-substituted indoles.

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Communication | Regular issue | Vol 34, No. 7, 1992, pp.1299-1301
Published online:
DOI: 10.3987/COM-92-6068
Incartine, a Biosynthetic Intermediate, from the Flowers of Lycoris incarnata

Masaru Kihara,* Lai Xu, Keiji Konishi, Yoshimitsu Nagao, Shigeru Kobayashi, and Tetsuru Shingu

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

Abstract

Incartine (3), a biosynthetic intermediate from galanthine (1) to narcissidine (2), was isolated along with galanthine (1) from the flowers of Lycoris incarnata.

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Paper | Regular issue | Vol 34, No. 7, 1992, pp.1303-1309
Published online:
DOI: 10.3987/COM-91-5889
Alkylation of 3-Ethyl-2-methyl-4-oxo-4,5,6,7-tetrahydroindole with Bromoesters: Benzenesulfonyl as Convenient Nitrogen Protecting Group

Christian F. Masaguer, Enrique Ravina,* and Javier Fueyo

*Department of Organic Chemistry, Laboratory of Pharmaceutical Chemistry, Faculty of Pharmacy, University of Santiago de Compostela, 15706 Santiago de Compostela, Spain

Abstract

α-Alkylation of 3-ethyl-2-methyl-4-oxo-1H-4,5,6,7-tetrahydroindole (3) with bromoesters gives 3-ethyl-2-methyl-4-oxo-1H-4,5,6,7-tetrahydro-5-indoleacetate (5a), 3-ethyl-2-methyl-4-oxo-1H-4,5,6,7-tetrahydro-5-indole-2-propionate (5b), and 3-ethyl-2-methyl-4-oxo-1H-4,5,6,7-tetrahydro-5-indole-3-propionate (6).

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Paper | Regular issue | Vol 34, No. 7, 1992, pp.1311-1315
Published online:
DOI: 10.3987/COM-91-5929
A Synthesis of 3-Hydroxymethyl-6-methylbenzofuran

Antonio G. González, Jaime Bermejo Barrera,* and Carlos Yanes Hernández

*Centro de Productos Naturales Orgánicos Antonio González, Consejo Superior de Investigaciones Científicas, Carretera de La Esperanza 2, 38206 La Laguna, Tenerife, Canary Islands, Spain

Abstract

3-Hydroxymethyl-6-methylbenzofuran, a thymol derivative recently isolated from Ageratina glechonophylla, has now been synthesized.

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Paper | Regular issue | Vol 34, No. 7, 1992, pp.1317-1324
Published online:
DOI: 10.3987/COM-92-5998
Thienocyclopenta[2,3-b]aziridin-5-one: Cleavage in Acidic Medium

Patrick Dallemagne, Juan Carlos Pilo, Sylvain Rault, Max Robba,* Michel Saux, and Alain Carpy

*Laboratoire de Chimie Thérapeutique, U. F. R. des Sciences Pharmaceutiques, 1 rue Vaubénard, 14032 CAEN cedex, France

Abstract

Cleavage of thienocyclopenta[2,3-b]aziridin-5-one leads to cis and trans isomers of hydroxyoxocyclopenta[b]thienylammonium chlorides whose structures are established by X-ray analysis and unequivocal synthesis. The mechanism of cleavage is studied.

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Paper | Regular issue | Vol 34, No. 7, 1992, pp.1325-1342
Published online:
DOI: 10.3987/COM-92-6011
Hydrolysis of Cyclic 2-Alkoxyiminium Salts

Charles A. Zezza, Tae Woo Kwon, JennLine Sheu, and Michael B. Smith*

*Department of Chemistry, U-60, Rm.151, 215 Glenbrook Rd., University of Connecticut, Storrs, Connecticut 06269-3060, U.S.A.

Abstract

N-Alkenyl- and N-alkoxymethyllactams are readily prepared from the corresponding lactam, and reaction with triethyloxonium tetrafluoroborate generates an 2-ethoxyiminium salt. Hydrolysis in neutral water gives the ethyl ester of 4-aminobutanoic acid (GABA)(or another ω-amino ester), an aldehyde and , in the case of the alkoxymethyl derivatives, an alcohol. The hydrolysis step requires participation of an enamine or N-Alkoxymethyl moiety in a proton exchange reaction prior to fragmentation of the ring. The reaction shows steric effect at the ‘enamine’ or N-alkoxymethyl terminus and some dependence on the size of the ring. The alkoxymethyl derivatives hydrolyze much slower than the alkenyllactam derivatives.

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Paper | Regular issue | Vol 34, No. 7, 1992, pp.1343-1352
Published online:
DOI: 10.3987/COM-92-6020
Synthesis and Configurational Study of 2-Arylmorpholines

Raymond Houssin, Marie-Pierre Vaccher, Jean-Pierre Hénichart, and Daniel Lesieur*

*Institut de Chimie Pharmaceutique, Université de Lille II, B.P. 83, 59006 Lille, France

Abstract

The synthesis of various 2-(2,3-dihydro-3-methyl-2-oxobenz[d]oxazol-6-yl)morpholines is reported. It has been demonstrated that 2-hydroxymorpholines or β-hydroxyethylaminomethyl ketones are formed as intermediates as assessed by ir, uv, 1H and 13C nmr analyses. The configuration of the title compounds was also established and corresponds to an equatorial orientation of the aromatic substituent which is considered as essential for an adrenergic activity.

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Paper | Regular issue | Vol 34, No. 7, 1992, pp.1353-1364
Published online:
DOI: 10.3987/COM-92-6021
Synthesis of 11H-Furo[3’,2’:7,8]benzopyrano[3,4-c]pyridin-11-one and 6,8-Dimethyl-10H-pyrano[2’,3’:4,5]benzofuro[3,2-c]pyridin-10-one (Pyridoangelicins)

Jacqueline Moron,* Christiane Huel, and Emile Bisagni

*URA 1387, CNRS, Institut Curie, Section de Biologie, Centre Universitaire, Bat. 110-112, 91405 Orsay, France

Abstract

11H-Furo[3’,2’:7,8]benzopyrano[3,4-c]pyridin-11-one (3) was synthesized from 1-benzyl-3-ethoxycarbonylpiperidin-4-one and 2,3-dihydro-4-hydroxybenzofuran (5) ba a von Pechmann reaction and subsequent aromatization of the hexahydro derivative (6). 6,8-Dimethyl-10H-pyrano[2’,3’:4,5]benzofuro[3,2-c]pyridin-10-one (4a) was obtained by dehydrogenation of the tetrahydro derivative (10b). This compound was prepared from piperidinone-O-(4,6-dimethylcoumarin-7-yl) oxime (9d) using acid catalyzed Fischer indole-like reaction. Are also reported and compared the results of the reactions of piperidinone-O-(coumarin-7-yl) oxime (9d) and the corresponding 5-methyl (9e) derivative, in which the rearrangement occurs at both the 8 and the 6 positions.

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Paper | Regular issue | Vol 34, No. 7, 1992, pp.1365-1373
Published online:
DOI: 10.3987/COM-92-6024
Phase Transfer Catalysis without Solvent. Synthesis of Bisazolylalkanes

Enrique Díez-Barra,* Antonio de la Hoz, Ana Sánchez-Migallón, and Juan Tejeda

*Facultad de Química, Universidad de Castilla-La Mancha, 13071 Ciudad Real, Spain

Abstract

The reaction of azoles and benzazoles with dihalomethanes and dihaloethanes was performed in the absence of solvent. This method provides a general procedure for the synthesis of bisazolylmethanes and ethanes. No solvent was used during the reaction and, when possible, during the work-up.

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Paper | Regular issue | Vol 34, No. 7, 1992, pp.1375-1384
Published online:
DOI: 10.3987/COM-92-6025
Studies on the Synthesis of C-2 Substituted Cephalosporin Sulfones: The Unexpected Reactivity of the C-2 Carbon

Maurizio Botta,* Marcello Crucianelli, Raffaele Saladino, and Rosario Nicoletti*

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

Abstract

An interesting route for the synthesis of C-2 substituted cephalosporin sulfones (8) has been described along with an unexpected reactivity on the C-2 carbon of C-2 substituted cephalosporin sulfoxides and sulfones.

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Paper | Regular issue | Vol 34, No. 7, 1992, pp.1385-1393
Published online:
DOI: 10.3987/COM-92-6031
Nitroimidazolones. Synthesis of Deaza Analogues of 3-Nitro-1,2,4-triazol-5-one

John E. Marlin* and Michael O. Killpack

*Frank J. Seiler Research Laboratory, U.S.A.F. Academy, CO 80840, U.S.A.

Abstract

Analogues of 3-nitro-1,2,4-triazol-5-one (NTO) have been synthesized. The strategy revolves around a new method for the synthesis of imidazolones, namely the addition-elimination reaction of the sodium salt of trimethylsilylethanol with a trimethylsilylethoxymethyl (SEM)-protected dinitroimidazole followed by the acid-catalyzed conversion to the desired nitroimidazole (5). The N-methyl derivatives of 5 were prepared in a similar manner starting from the N-methyldinitroimidazoles.

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Paper | Regular issue | Vol 34, No. 7, 1992, pp.1395-1398
Published online:
DOI: 10.3987/COM-92-6033
Synthesis of 5-Arylated Indoles via Palladium-catalyzed Cross-coupling Reaction of 5-Indolylboronic Acid with Aryl and Heteroaryl Halides

Youhua Yang and Arnold R. Martin*

*Department of Pharmaceutical Sciences, College of Pharmacy, University of Arizona, Tucson, AZ 85721, U.S.A.

Abstract

Palladium(0)-catalyzed cross-coupling reaction of 5-indolylboronic acid with various aryl and heteroaryl halides results in regioselective formation of 5-arylated indoles in good yields.

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Paper | Regular issue | Vol 34, No. 7, 1992, pp.1399-1413
Published online:
DOI: 10.3987/COM-92-6037
An Experimental and Theoretical Study on 4-Amino-1,2,3-triazolo-1,2,6-thiadiazine 2,2-Dioxide Tautomers and Their N-Amino and N-Methyl Derivatives

Angela Herrero, M. Luisa Jimeno, Carmen Ochoa,* José L. G. de Paz, Concepción Foces-Foces, Félix H. Cano, and Martín Martínez-Ripoll

*Instituto de Química Médica, C. S. I. C., Juan de la Cierva, 3. 28006 Madrid, Spain

Abstract

The synthesis of 4,5-diaminotriazolothiadiazine dioxide (4c) is described. The carbon-13 and nitrogen-15 chemical shifts of 4-amino-1,2,3-triazolo-1,2,6-thiadiazine 2,2-dioxide (1), its 1,6-dimethyl derivative (3b) and 4c are reported. Compound (4c) has been studied by X-ray crystallography. The experimental preference for the 1H, 6H-tautomer, 1,6-dimethyl and 5-amino isomers is discussed.

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Paper | Regular issue | Vol 34, No. 7, 1992, pp.1415-1422
Published online:
DOI: 10.3987/COM-92-6040
[8+2]-Type cycloaddition Reactions of N-Aryl-2,4,6-cycloheptatriene-1-imines and 2,4,6-Cycloheptatriene-1-thione with p-Toluenesulfonyl Isocyanate: Formation of 1,3-Diazaazulanones

Kazuaki Ito, Katsuhiro Saito,* Shigeyuki Takeuchi, and Kensuke Takahashi

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

Abstract

Reactions of N-aryl-2,4,6-cycloheptatriene-1-imines and 2,4,6-cycloheptatriene-1-thione with p-toluenesulfonyl isocyanate gave [8+2]-type cycloadducts in good yields. Eliminations of tosyl groups and dehydrogenations of the adducts afforded 1,3-diazaazulanones.

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Paper | Regular issue | Vol 34, No. 7, 1992, pp.1423-1434
Published online:
DOI: 10.3987/COM-92-6071
The Reactions of 2,6-Dichlorobenzonitrile Oxide with Pyrimidine Derivatives

Jae Nyoung Kim and Eung K. Ryu*

*Division of Organic Chemistry, Korea Research Institute of Chemical Technology, P.O.Box 9, Daedeog Danji, Daejeon 305-606, Korea

Abstract

The reactions of 2,6-dichlorobenzonitrile oxide with various kinds of pyrimidine derivatives (2a-g, 5-14) in different reaction conditions were studied.

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Paper | Regular issue | Vol 34, No. 7, 1992, pp.1435-1441
Published online:
DOI: 10.3987/COM-92-6081
A Facile and Convenient Synthetic Method for 3-Trifluoroacetylpyrroles

Etsuji Okada, Ryoichi Masuda, Masaru Hojo,* and Reiko Yoshida

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

Abstract

3-Trifluoroacetylpyrroles are easily obtained in excellent yields by oxygen-nitrogen exchange reaction of β-trifluoroacetylvinyl ethers with 2,2-dimethoxyethylamie and subsequent cyclodehydration of the products.

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20 data found. 1 - 20 listed