Regular Issue

Vol. 48, No. 7, 1998

22 data found. 1 - 22 listed
Communication | Regular issue | Vol 48, No. 7, 1998, pp.1307-1312
Published online:
DOI: 10.3987/COM-98-8138
Product Structure as a Function of Reaction Conditions in the Reaction of Formaldehyde with an Alpha-Mercapto Amide

James D. Copp,* Francis O. Ginah, Marvin M. Hansen, Douglas P. Kjell, and Brian J. Slattery

*Chemical Process Research and Development Division, Lilly Reserach Laboratories, Eli Lilly & Company, Lilly Corporate Center, Indianapaolis, IN 46285-4813, U.S.A.

Abstract

Treatment of mercapto amide (3) with formaldehyde and acid or base results in products whose structures are a function of the reaction conditions. Lactone (8), hemithioacetal (9), and dimer (7) were formed in good yields under acidic reaction conditions. In addition, dienenone (10) was produced from the treatment of (9) with strongly coordinating Lewis acids. Treatment of (9) with NH3/MeOH gave the desired thiazolidinone (1) in moderate yield.

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Communication | Regular issue | Vol 48, No. 7, 1998, pp.1313-1317
Published online:
DOI: 10.3987/COM-98-8148
Model Studies toward the Synthesis of Na-Acetyl-Nb-methylphlegmarine: Addition of Cyclohexylmethyl Organometallics to 1-Acylpyridinium Salts

Daniel L. Comins,* Chris J. Foti, and Adam H. Libby

*Department of Chemistry, North Carolina State Univesity, P. O. Box 8204, Raleigh, NC 27695-8204, U.S.A.

Abstract

Addition of various cyclohexylmethyl organometallics to a chiral 1-acylpyridinium salt was investigated as a model study toward the asymmetric synthesis of the Lycopodium alklaoid, phlegmarine (1d).

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Communication | Regular issue | Vol 48, No. 7, 1998, pp.1319-1324
Published online:
DOI: 10.3987/COM-98-8152
Total Synthesis of Macrocyclic Antibiotic, Micrococcin P1

Kazuo Okumura, Akinori Ito, Dai Yoshioka, and Chung-gi Shin*

*Laboratory of Organic Chemistry, Faculty of Technology, Kanagawa University, 3-27-1 Rokkakubashi, Kanagawa-ku, Yokohama 221-8686, Japan

Abstract

Total synthesis of a macrocyclic antibiotic, micrococcin P1 (1), constructed from four segments called Fragmetns, A, B, C, and D, was achieved. The synthesis of a central 2,3,6-trithiazole-substituted pyridine moiety [Fragment A with C (A-C)], followed by coupling with Fragments B and D synthesized independently gave the protected Fragment A-B-C-D. Final deprotection of all the protecting gourps and cyclization gave synthetic 1.

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Communication | Regular issue | Vol 48, No. 7, 1998, pp.1325-1330
Published online:
DOI: 10.3987/COM-98-8161
Stereocontrolled Synthesis of Tetrahydrofurans and Tetrahydropyrans by Cyclisation of Hydroxyselenides

Luca Arista, Michelangelo Gruttadauria,* and Renato Noto

*Dipartimento di Chimica Organica, Universita di Palermo, Via Archirafi 20 90123 Palermo, Italy

Abstract

An efficient stereocontrolled synthesis of 2,3,5-trisubstituted tetrahydrofuran and 2,4,6-trisubstituted tetrahydropyran rings from homoallylic alcohols (16) and (18) was achieved by: i) epoxidation; ii) ring opening of the epoxide with sodium phenyl selenide; iii) cleavage of the TBDMS group with a stereoconvergent elimination of water followed by intramolecular oxygen nucleophile capture. The presence of a branching near to the selenonium ring made the attack in the exo mode faster than the attack in the endo/exo mode.

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Communication | Regular issue | Vol 48, No. 7, 1998, pp.1331-1335
Published online:
DOI: 10.3987/COM-98-8163
A Novel Synthesis of 1,3-Benzodiazepin-2-ones Using Intramolecular Heck Reaction

Masahito Hayashi, Hiroshi Sai, and Hiroshi Horikawa*

*Lead Optimization Research Laboratory, Tanabe Seiyaku Co.Ltd., 2-2-50, Kawagishi, Toddda, Saitama 335-8505, Japan

Abstract

The formation of the skeleton of 1,3-benzodiazepin-2-one could be efficiently achieved by intramolecular Heck reaction. This methodology was well applicable to the preparation of optically pure 4-substituted 1,3-benzodiazepin-2-ones starting from easily available α-amino acids.

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Communication | Regular issue | Vol 48, No. 7, 1998, pp.1337-1342
Published online:
DOI: 10.3987/COM-98-8166
Synthesis and Reactions of Chiral Cyclic Nitrones Derived from D-Ribose

Cedric W. Holzapfel* and Renier Crous

*Department o f Chemistry and Biochemistry, Rand Afrikaans University, P.O. Box 524, Auckland Park, 2006, Johanesberg, South Africa

Abstract

A facile route to chiral cyclic nitrones derived from D-ribose is described. Their versatility as substrates for 1,3-dipolar cycloadditions and nucleophilic additions is demonstrated.

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Communication | Regular issue | Vol 48, No. 7, 1998, pp.1343-1346
Published online:
DOI: 10.3987/COM-98-8175
Conambine, a New Norditerpenoid Alkaloid from Consolida ambigua Seeds

Haridutt K. Desai and S. William Pelletier*

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

Abstract

A new norditerpenoid alkaloid, "conambine" (1) has been isolated from the seeds of Consolida ambigua L. Its structure has been established on the basis of its spectroscopic data and chemical correlation with anthranoyllycoctonine (3).

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Paper | Regular issue | Vol 48, No. 7, 1998, pp.1347-1363
Published online:
DOI: 10.3987/COM-98-8108
Synthesis and Stability of 5-, 7- and 8-Substituted Benzo-1,2,3,5-tetrazepin-4-ones

Bertrand J. Jean-Claude* and George Just

*Department of Chemistry, McGill University, 7 Montreal, Quebec H3A 2K6, Canada

Abstract

In order to determine the effect of substituents on the stability of benzo-fused 1,2,3,5-tetrazepin-4-ones, 5-,7- and 8-substituted derivatives (6a-d), and (10) were synthesized. The stability of the tetrazepinones increased with the electron withdrawing character of the substituents at the benzene ring. Bulky groups at the 5 position destabilize the tetrazepinone ring. The unstable tetrazepinones (6b, 10 and 14) decomposed in chloroform at room temperature to benzotriazole derivatives (11, 12, and 15). X-Ray diffraction of nitrobenzotetrazepinone (6d) showed that despite the electron withdrawing effect of the nitro group para to the triazene chain, N3 exhibited a significant pyramidal character. In 6d, the 1,2,3,5-tetrazepinone cycle has an almost perfect seven-membered ring boat shape.

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Paper | Regular issue | Vol 48, No. 7, 1998, pp.1365-1371
Published online:
DOI: 10.3987/COM-98-8118
Synthesis of Furanonaphthazarin Derivatives

Ricardo A. Tapia,* Miriam C. Gárate, Jaime A. Valderrama, and Paul R. Jenkins

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

Abstract

A three-step synthesis of the 5,8-dihydroxy-2-(1-methylethyl)naphtho[2,3-b]furan-4,9-dione (9) starting from 2-hydroxy-5,8-dimethoxy-1,4-naphthoquinone (4), is described. Further treatment of (9) with selenium dioxide in the presence of pyridine N-oxide as co-oxidant gave 2-(1-hydroxy-1-methylethyl)naphtho[2,3-b]furan-4,9-dione (10).

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Paper | Regular issue | Vol 48, No. 7, 1998, pp.1373-1394
Published online:
DOI: 10.3987/COM-98-8149
The Direct Synthesis of Isoflavans via α-Alkylation of Phenylacetates

Marietjie Versteeg, Barend C. B. Bezuidenhoudt, and Daneel Ferreira*

*Department of Chemistry, University of Orange Free State, P.O. Box 339, Bleoemfontien, 9300, South Africa

Abstract

Deprotonation of oxygenated phenylacetates and quenching of the enolates with oxygenated benzylic electrophiles, afforded 2,3-diarylpropanoates which served as precursors to the isoflavans following consecutive reduction and cyclization steps.

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Paper | Regular issue | Vol 48, No. 7, 1998, pp.1395-1406
Published online:
DOI: 10.3987/COM-98-8162
Acylation of Guanylhydrazones Derived from Cyclic Ketones: Synthesis of 3-Acylamino-1-cycloalkenyl-5-methyl-1H-1,2,4-triazoles

Zoltan Györgydeák and Wolfgang Holzer*

*Institute of Pharmaceutical Chemistry, University of Vienna, Währinger Strasse 14, A-1090 Vienna, Austria

Abstract

Reaction of guanylhydrazones derived from different cycloalkanones, 1-indanone and 4-chromanone, respectively, with excessive acetic anhydride leads to the formation of 3-acetylamino-1-cycloalkenyl-5-methyl-1H-1,2,4-triazoles. However, with camphor guanylhydrazone only the corresponding N,N’-diacetylguanylhydrazone was obtained, whereas 2-adamantone guanylhydrazone afforded 2-(3-acetylamino-5-methyl-1,2,4-triazol-1-yl)-2-adamantyl acetate. Detailed NMR spectroscopic studies (1H, 13C) with the title compounds and their guanylhydrazone precursors are presented.

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Paper | Regular issue | Vol 48, No. 7, 1998, pp.1407-1414
Published online:
DOI: 10.3987/COM-98-8171
Transformation of Oxomethanobenzocyclooctenecarboxylic Acids to Pyrrolidinone-fused Penta-, Hexa- and Heptacyclic Hetero Compounds

Ferenc Miklós, Géza Stájer,* Pál Sohár, Gábor Bernáth, and Reijo Sillanpää

*Institute of Pharmaceutical Chemistry, Albert Szent-Györgyi Medical University, POB 121, H-6701 Szeged, Eötvös u. 6, Hungary

Abstract

10-Oxo-5r,6,7,8c,9c,10-hexahydro-5,9-methanobenzocyclooctene-8-carboxylic acid (1a) or a C-8 epimeric mixture (1a and 1b) reacted with 1,2-, 1,3- and 1,4-bifunctional reagents, 1,2- or 1,3-diaminopropane (2, 3), 1,2- or 1,3-propanolamine (4, 5), 1,4-diaminobutane (6), o-aminothiophenol (7), diexo-3-aminobicyclo[2.2.1]heptane-2-methanol or diendo-3-aminobicyclo[2.2.1]hept-5-ene-2-methanol (8, 9), to produce polycyclic compounds containing a pyrrolo-condensed pyrimidine (10), imidazole (11), 1,3-oxazine (12, 16, 17), oxazole (13), 1,3-diazepine (14), benzthiazole (15) moiety and one or two terminal aromatic rings by cyclization. The structures of 10-17 were established by 1H and 13C NMR spectroscopy and for 16 also by X-Ray analysis.

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Paper | Regular issue | Vol 48, No. 7, 1998, pp.1415-1422
Published online:
DOI: 10.3987/COM-98-8176
Preparation and Absorption Spectral Properties of the Nitrogen Analogs of a Pechmann Dye and Its Isomeric Pyrano[4,3-c]pyran-1,5-dione

Hajime Irikawa,* Norihide Adachi, and Hirokazu Muraoka

*Department of Chemisttry, Faculty of Science, Shizuoka University, Ohya, Shizuoka 422-8529

Abstract

Bathochromic shifts were observed by replacement of the lactone-oxygen atoms in a Pechmann dye with nitrogen atoms, while hypsochromic shifts were caused by replacement of the lactone-oxygen atoms in a pyrano[4,3-c]pyran-1,5-dione with nitrogen atoms.

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Paper | Regular issue | Vol 48, No. 7, 1998, pp.1423-1430
Published online:
DOI: 10.3987/COM-98-8178
Synthesis and Antitumoral Evaluation of 12-Substituted 6,7-Dihydrobenzo[4,5]-cyclohept[1,2-b]indole Derivatives

Benoît Joseph, Virginie Chapellier, Jean-Yves Mérour,* and Stéphane Léonce

*Instiut de Chimie Organique et Analytique, U. F. R. de Sciences, Université d'Orléans, BP 6759, Rue de Chartres, 45067 Orleans Cedex 2, France

Abstract

The synthesis of 12-substituted 6,7-dihydrobenzo[4,5]cyclohept[1,2-b]indole derivatives (2-3) are described. The antiproliferative activity of some of them were evaluated.

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Paper | Regular issue | Vol 48, No. 7, 1998, pp.1431-1444
Published online:
DOI: 10.3987/COM-98-8180
Synthesis, 1H and 13C NMR Spectra, and Configurational Assigment of Furfurylideneimidazolinones

Peter Schuisky, Wolfgang Twistel, and Spiros Grivas*

*Department of Organic Chemistry, Södertörn University College, Karolinska Institutet, Novum Research Park, SE-141 57 Huddinge, Sweden

Abstract

The title compounds (14 and 15) were obtained by the condensation of a 2- or 3-furaldehyde derivative (prepared from 2-methylfuran) with 2-amino-1-methyl-2-imidazolin-4-one (6) or 5-one (7). Most products from 6 contained the (E)- and (Z)-isomers in comparable amounts; in those from7, the (Z)-isomer generally predominated. The isomers were distinguished by their 1H and 13C NMR spectra, in particular by the three-bond coupling between the carbonyl carbon and the olefinic hydrogen. This led to configurational reassignment of some previously reported analogues.

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Paper | Regular issue | Vol 48, No. 7, 1998, pp.1445-1453
Published online:
DOI: 10.3987/COM-98-8183
Amine N-Oxides Derived from Alkaloids as Chiral Promoters in Enantioselective Pauson-Khand Reactions

Volker Derdau, Sabine Laschat,* and Peter G. Jones

*Institut für Organische Chemie, Technische Universität Braunschweig, Hagenring 30, D-38106 Braunschweig, Germany

Abstract

The novel indolizino[3,4-b]quinoline N-oxide (12) was prepared and characterized by X-Ray crystal structure determination. Compound (12) and sparteine N-oxides (8 - 10) were employed as chiral promoters in the Pauson-Khand cocyclization of various alkynes (1) with norbornene (4) to the bicyclic cyclopentenones (6) with enantioselectivities up to 33 %ee.

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Note | Regular issue | Vol 48, No. 7, 1998, pp.1455-1459
Published online:
DOI: 10.3987/COM-98-8125
Oxidation of 1,3-Dimethylthymine and 1,3-Dimethyluracil with Oxone® in the Solid to Solid State

Yongrae Hong, Soonjae Chang, Bosup Hahn,* and Fumio Toda

*Department of Chemistry, Ajou University, 5 Wonchun, Suwon 442-749, Korea

Abstract

The oxidation of the title substrates with Oxone® in the presence of camphor in the solid to solid state afforded a simple and efficient method for epoxidation under mild reaction condition.

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Note | Regular issue | Vol 48, No. 7, 1998, pp.1461-1464
Published online:
DOI: 10.3987/COM-98-8142
Axinellamines A and B, New Pyrrole Alkaloids of the Marine Sponge Axinella Sp.

Karen C. Bascombe, Sonia R. Peter, Winston F. Tinto,* Suzanne M. Bissada, Stewart McLean, and William F. Reynolds*

*Laboratory of Bioorganic Chemistry, Department of Biological Chemical Sciences, University of the West Indies, Cave Hill Campus, P.O. Box 64, Bridgetown, Barbados, West Indies

Abstract

Two new pyrrole alkaloids, axinellamines A and B, were isolated from the Caribbean marine sponge Axinella sp. and their structures were established on the basis of spectroscopic data, including 2D NMR spectroscopy. Axinellamine A was determined to be 2-((E,E)-6-methyl-2,4-octadienyl)pyrrole while axinellamine B was a dimer of axinllamine A, but containing an additional Me2C unit between the C-5 and C-5’ carbons of the two pyrrole rings.

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Note | Regular issue | Vol 48, No. 7, 1998, pp.1465-1469
Published online:
DOI: 10.3987/COM-98-8159
Caesalpinin B, a Rearranged Cassane Furanoditerpene of Caesalpinia bonduc

Deon L. Lyder, Winston F. Tinto,* Suzanne M. Bissada, Stewart McLean, and William F. Reynolds*

*Laboratory of Bioorganic Chemistry, Department of Biological Chemical Sciences, University of the West Indies, Cave Hill Campus, P.O. Box 64, Bridgetown, Barbados, West Indies

Abstract

A new rearranged cassane furanoditerpenone, caesalpinin B, was isolated from the roots of Caesalpinia bonduc, collected in Barbados, West Indies. The structure was established on the basis of spectroscopic data, including 2D NMR spectroscopy.

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Note | Regular issue | Vol 48, No. 7, 1998, pp.1471-1476
Published online:
DOI: 10.3987/COM-98-8169
Kinetic Resolution of Aryl Glycidyl Ethers: A Practical Synthesis of Optically Pure β-BlockerS-Metoprolol

Mukund K. Gurjar,* Kashinath Sadalapure, Susanta Adhikari, Bugga V. N. B. S. Sarma, Arindam Talukdar, and Mukund S. Chorghade

*Organic Chemistry Division III, Indian Institute of Chemical Technology, Hyderabad 500 007, India

Abstract

Kinetic resolution of (±)-aryl glycidyl ethers using (R,R)-salen Co(III)OAc and water provided enantiomerically pure arylglycidyl ether and 1-arylglycerol derivatives with high enantiomeric excess. Application of this approach to (S)-metoprolol has been described.

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Note | Regular issue | Vol 48, No. 7, 1998, pp.1477-1481
Published online:
DOI: 10.3987/COM-98-8181
Synthesis, Complexation and Emission Behavior of N,N',N'',N'''-Tetrakis-(1-naphthylmethyl)-1,4,8,11-tetraazacyclotetradecane

Kanji Kubo,* Emi Yamamoto, and Tadamitsu Sakurai

*Instituete of Advanced Material Study, Kyushu University, 6-1, Kasuga-koen, Kasuga 816-8580, Japan

Abstract

Cyclam derivative (2) having four naphthylmethyl pendants was found to display unique photophysical properties in the presence of the guest metal salts. The fluorescence of the cyclam (2) was enhanced with various metal salts. The photoinduced electron transfer (PET) sensor (2) exhibited high Zn2+ selectivty.

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Review | Regular issue | Vol 48, No. 7, 1998, pp.1483-1492
Published online:
DOI: 10.3987/REV-98-498
Biomimetic Formation and Interconversion in the Heteroyohimbine Series

Mauri Lounasmaa* and Pirjo Hanhinen

*Laboratory for Organic and Bioorganic Chemistry, Technical University of Helsinki, P.O. Box 6100, FIN-02150 HUT Espoo, Finland

Abstract

A general scheme, based on three currently accepted transformation reactions, is proposed for the biomimetic formation and interconversion of the four possible Δ20(21)-didehydroheteroyohimbines (cathenamines)(4, 9-11). The reactions permit, after reduction, access to all eight basic heteroyohimbine alkaloids (6-8, 12-16).

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22 data found. 1 - 22 listed