Special Issue

Volume 50's Special Issues, Vol. 50, No. 2, 1999

51 data found. 31 - 51 listedFirst Previous
Paper | Special issue | Vol 50, No. 2, 1999, pp.913-918
Published online:
DOI: 10.3987/COM-98-S(H)90
An Efficient Route to Formyldeuteroporphyrins and Their Wittig Reaction

Akira Ando, Miyuki Yamazaki, Mika Komura, Yuka Sano, Nami Hattori, Masaaki Omote, and Itsumaro Kumadaki*

*Faculty of Pharmaceutical Sciences, Setsunan University, 45-1, Nagaotoge-cho, Hirakata-shi, Osaka 573-0101, Japan

Abstract

Copper complex of deuteroporphyrin dimethyl ester (2) was formylated with trimethyl orthoformate in the presence of tin(IV) chloride, followed by demetallation with H2SO4-CF3COOH and separation by column chromatography to give 3- (5) and 8-formyl compounds (6) in 46 and 47% yields, respectively. The Wittig reaction of these formylporphyrins gave highly functionallized derivatives of porphyrin.

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Paper | Special issue | Vol 50, No. 2, 1999, pp.919-928
Published online:
DOI: 10.3987/COM-98-S(H)92
Rearrangement Reaction of Tetrahydrofurans and Tetrahydropyrans Having a C1'-Mesyloxy Group on the C2-Side Chain with Zinc Acetate

Kazuo Nagasawa, Nobuyuki Hori, Hiroyuki Koshino, and Tadashi Nakata*

*The Institute of Physical and Chemical Research, Wako-shi, Saitama 351-0198, Japan

Abstract

Rearrangements of tetrahyrofurans and tetrahydropyrans having a C1'-mesyloxy group on the C2-side chain with zinc acetate in aq. AcOH were investigated. Rearrangement-ring expansion and/or rearrangement-ring opening reactions took place depending on the stereostructure of the substrates.

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Paper | Special issue | Vol 50, No. 2, 1999, pp.929-945
Published online:
DOI: 10.3987/COM-98-S(H)93
Regioselectivity of 1,3-Dipolar Cycloaddition of 3-Oxidopyridinium Betaines to Olefins and Stereoselective Synthesis of 6-Alkyloxy-5-oxa-9-azatricyclo[5.2.1.04,8]decan-2-one Derivatives

François Estour, Stéphane Rézel, Didier Fraisse, Jacques Métin, Vincent Gaumet, Claire Lartigue, Gilles Miscoria, Alain Gueiffier, Yves Blache, Jean C. Teulade, and Olivier Chavignon*

*Départment d'Analyse Structurale et de Pharmacologie, Faculté de Pharmacie, UMR INSERM 484, 28 Pl. H. Dunant, B. P. 38, 63001 Clermont-Ferrand Cedex 1, France

Abstract

A new method to obtain the four isomers of tropane skeleton by dipolar addition of 3-oxidopyridinium betaines to activated olefins is described, and a general synthetic strategy for tricyclic tropane homologues is also reported.

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Paper | Special issue | Vol 50, No. 2, 1999, pp.947-967
Published online:
DOI: 10.3987/COM-98-S(H)94
Preparation of 2-Alkylselenobenzothiazoles by the Reaction of Alcohols with 2-(2-Oxoethylseleno)benzothiazoles in the Presence of Tertiary Phosphines

Koichi Shibata,* Hiko Yamaga, and Oyo Mitsunobu*

*Department of Chemistry, College of Science and Engineering, Aoyama Gakuin University, 6-16-1 Chitosedai, Setagayaku, Tokyo 157-8572, Japan

Abstract

Reactions of alcohols with 2-(1,2-diphenyl-2-oxoethylseleno)benzothiazole in the presence of Bu3P gave the corresponding 2-alkyselenobenzothiazoles, where inversion of the secondary carbinol center of the alcohols took place. 1,3-Butanediol reacted at the primary hydroxyl group, while 1-phenyl-1,2-ethanediol reacted at the secondary hydroxyl group.

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Paper | Special issue | Vol 50, No. 2, 1999, pp.969-980
Published online:
DOI: 10.3987/COM-98-S(H)95
A Concise Synthesis of (+)-α-Allokainic Acid via Site- and Diastereoselective Intramolecular C-H Insertion Process

Masahiro Anada, Tomohiro Sugimoto, Nobuhide Watanabe, Makoto Nakajima, and Shun-ichi Hashimoto*

*Graduate School of Pharmaceutical Science, Hokkaido University, Sapporo 060-0812, Japan

Abstract

A new route to (+)-α-allokainic acid commencing with L-serine has been established, wherein the key step involves a C3, C4 bond formation with a simultaneous creation of a C2,C3-trans and C3,C4-trans arrangement of substituents by Rh2(OAc)4-catalyzed C-H insertion reaction of α-diazoacetoacetamide tethered to (S)-4-(3-butenyl)-2,2-dimethyl-1,3-oxazolidine system. Taber's computaional model confirms the observed diastereomer preference.

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Paper | Special issue | Vol 50, No. 2, 1999, pp.981-988
Published online:
DOI: 10.3987/COM-98-S(H)96
Synthesis of Solamin

Wataru Kuriyama, Ken Ishigami, and Takeshi Kitahara*

*Department of Applied Biological Chemistry, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan

Abstract

Total synthesis of an annonaceous acetogenin, solamin (1) is described. Direct coupling between γ-lactone (13) and mono-THF unit (12) prepared from D-glutamic acid in 16 steps gave the product (14) in excellent yield, which was converted to the title compound (1) in sequential 3 steps.

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Paper | Special issue | Vol 50, No. 2, 1999, pp.989-994
Published online:
DOI: 10.3987/COM-98-S(H)98
Dual p-Coumaroyl CoA Biosynthesis in Morus alba Cell Cultures

Yoshio Hano, Manabu Shimazaki, Taro Nomura,* and Shinichi Ueda

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

Abstract

Morus alba callus and cell suspension cultures specifically produce chalcomoracin (1) and kuwanon J (2) both originated from cinnamoylpolyketide intermediate. Administration of [2-13C]cinnamic acid N-acetylcysteamine thioester to the M. allba cell cultures revealed the cinnamoyl CoA intermediate to be a significant precursor. The present result, coupled with the parallel contribution of both L-phenylalanine and L-tyrosine to the same cinnamoyl part, gave a conclusive evidence for the route leading to p-coumaroyl CoA in the M. alba cell cultures.

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Paper | Special issue | Vol 50, No. 2, 1999, pp.995-1024
Published online:
DOI: 10.3987/COM-98-S(H)100
Diastereo- and Enantioselective Synthesis of Δ2-1,2,4-Oxadiazolines by 1,3-Dipolar Cycloaddition of Nitrile Oxides with Chiral Hydrazones

Dieter Enders,* Ilka Meyer, Jan Runsink, and Gerhard Raabe

*Institut für Organische Chemie, Rheinisch-Westfälische, Technische Hochsch, Professor-Pirlet-Strasse 1, D-52074 Aachen, Germany

Abstract

Diastereo- and enantioselective 1,3-dipolar cycloadditions of nitrile oxides (3) with α,β-unsaturated hydrazones (2) gave spiro oxadiazolines (4) in good yields and low to excellent diastereomeric excesses (de = 5->98%). Open chain hydrazones (6) afforded 5,5-disubstituted Δ2 -1,2,4-oxadiazolines (7). A subsequent N-N bond cleavage to remove the chiral auxiliary was achieved with formic acid and gave the oxadiazolines (8)(ee = 0 - 91%).

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Paper | Special issue | Vol 50, No. 2, 1999, pp.1025-1031
Published online:
DOI: 10.3987/COM-98-S(H)103
The Efficient Synthesis of 1,2-Dioxetanes from Indene and 1,2-Dihydronaphthalene

Charles W. Jefford* and Marcelo Ferrufino Deheza

*Department of Organic Chemistry, Laboratory fo Crystallography, University of Geneva, 30, quai Ernest Ansermet, 1211 Geneva 4, Switzerland

Abstract

Indel (1), 1-methylindene (7), 2-methylindene (10), 1,2- and 1,4-dihydronaphthalenes (3 and 18) were converted into their trans-1,2-bromo-hydroperoxides. The latter on treament with a mixture of Ag2O/AgSO2CF3 in CH2Cl2 at room temperture gave the corresponding 1,2-dioxetanes in yields of 90,88,80,80, and 50% respectively. The cis-disposed bromo-hydroperoxide obtained from 7 was unreactive on treatment with the silver mixture. Similar treatment of the trans-bromo-hydroperoxide obtained from 3,3-dimethylindene (14) was equally without effect, no dioxetane being formed.

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Paper | Special issue | Vol 50, No. 2, 1999, pp.1033-1039
Published online:
DOI: 10.3987/COM-98-S(H)106
Chiral Auxiliary Approach to the Asymmetric Pictet-Spengler Reaction of Tryptamines

Tomohiko Kawate, Masamichi Yamanaka, and Masako Nakagawa*

*Faculty of Pharmaceutical Sciences, Chiba University, 1-33 Yayoi-cho, Inage-ku, Chiba 263-8522, Japan

Abstract

The diastereoselective Pictet-Spengler reaction of chiral tryptamines bearing an α-naphthylethyl auxiliary group was investigated. In the presenceof trifluoroacetic acid as a catalyst, the Pictet-Spengler reaction of various aldehydes gave the corresponding tetrahydro-β-carbolines at a diastereoselectivity of up to 93 : 7.

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Paper | Special issue | Vol 50, No. 2, 1999, pp.1041-1063
Published online:
DOI: 10.3987/COM-98-S(H)108
Peptide Coupling Reactions with Phosphono-Phosphino Substituted γ-Thiapyrones — First Step to Unusual Peptides

Dirk Uwe Hahn and Richard Neidlein*

*Pharmazeutisch-Chemishces Institut, Ruprecht-Karls-Universität Heidelberg, Im Neuenheimer Feld 364, D-69120 Heidelberg, Germany

Abstract

The reaction of phosphono-phosphino substituted γ-thiapyrones (8/9) with pentafluorphenyldiphenylphosphinate - FDPP - (7) and protected α-L-amino acids (10) lead to chiral α-peptido substituted phosphono-phosphino γ-thiapyrones (12/13). Besides β-peptido- and peptoido substituted phosphono γ-thiapyrones (16/21) are synthesized in the presence of FDPP as an efficient peptide coupling reagent.

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Paper | Special issue | Vol 50, No. 2, 1999, pp.1065-1080
Published online:
DOI: 10.3987/COM-98-S(H)111
Synthesis of New Melatoninergic Ligands Including Azaindole Moiety

Daniel Mazéas, Gérald Guillaumet, and Marie-Claude Viaud*

*Laboratoire de Chimie Bioorganique et Analytique, associe au CNRS, Université d'Orléans, B.P. 6759, Rue de Chartres, 45067 Orleans Cedex 2, France

Abstract

A novel series of melatonin analogues, based on the azaindole nucleus is described. These compounds are prepared in several steps directly from the commercial available 7-azaindole or from substituted amino-, iodo- or/and nitropyridines using a catalysed palladium reaction or vicarious nucleophilic substitution of hydrogen (VNS) in order to elaborate the 6-, 5- and 4-azaindole derivatives derivatives respectively.

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Note | Special issue | Vol 50, No. 2, 1999, pp.1081-1090
Published online:
DOI: 10.3987/COM-98-S(H)52
A Convenient Approach to the Synthesis of the Imidazo[5,1-b]oxazole Ring System

Héctor Salgado-Zamora,* Elena Campos, Rogelio Jiménez, Esmeralda Sánchez-Pavón, and Humberto Cervantes

*Departamento de Químíca Orgánica, Escuela Nacional de Ciencias Biológicas, I. P. N., Prol. Carpio y Plan de Ayala S/N,11340, Mexico, D.F.

Abstract

Reaction of 4(5)-bromo-2-methyl-5(4)-nitroimidazol with phenacyl bromide derivatives led to 4-bromo-2-methyl-1-phenyl-1-phenacyl-5-nitro- and 5-bromo-2-methyl-1-phenacyl-4-nitroimidazoles. Treatment of the latter isomers with potassium tert-butoxide in dry THF yielded imidazo[5,1-b]oxazoles.

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Note | Special issue | Vol 50, No. 2, 1999, pp.1091-1096
Published online:
DOI: 10.3987/COM-98-S(H)79
Synthesis of a Novel Multi-Receptor Containing Hydrogen Bonding Sites and Ion Binding Sites

Tatsuya Nabeshima* and Takeshi Hanami

*Department of Chemistry, University of Tsukuba, 1-1-1 Ten-nodai, Tsukuba-shi, Ibaraki, 305-8571, Japan

Abstract

A new linear ditopic receptor (1) which contains two 2,6-diaminopyridine moieties and two 2,6-diaminopyridine moieties and two crown ether rings at the termini has been synthesized. The host (1) binds a thymine derivative and behaves as a ditopic receptor in a transpor in a transport experiment.

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Note | Special issue | Vol 50, No. 2, 1999, pp.1097-1104
Published online:
DOI: 10.3987/COM-98-S(H)107
Simple Syntheses of Thieno[4,3,2-d,e]isoquinoline-3,5-diones and Their Homologues

Ferenc Fülöp,* Bert Naumann, Gábor Günther, Gábor Bernáth, and Reijo Sillanpää

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

Abstract

Simple, convenient syntheses of thieno[4,3,2-d,e]isoquinoline-3,5-diones (7a-d) and their homologues (8a-c) were achieved strating from ethyl 2-amino-3-cyano-4,5,6,7-tetrahydrobenzo[b]thiophene-4-carboxylate (2) and its homologue derivatives (5) by sulfuric acid treatment.

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Note | Special issue | Vol 50, No. 2, 1999, pp.1105-1113
Published online:
DOI: 10.3987/COM-98-S(H)112
Synthetic Studies of Forskolin. A Formal Synthesis via a Nicolaou's Advanced Intermediate

Hsing-Jang Liu* and Xiao Shang

*Department of Chemistry, University of Alberta, Edmonton, Alberta, T6G 2G2, Canada

Abstract

A formal synthesis of (±)-forskolin (1) has been effected making use of enone (2) as a relay compound.

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Review | Special issue | Vol 50, No. 2, 1999, pp.1115-1136
Published online:
DOI: 10.3987/REV-98-SR(H)1
Towards a Unitary Description of the Photochemical Isomerization Reactions in Pentaatomic Aromatic Heterocycles: The Case of Furan, Thiophene, Pyrrole, Isoxazole, Imidazole, and Pyrazole Derivatives

Maurizio D’Auria

*Dipartamento di Chimica, Università della Basilicata, Via N. Sauro 85, 85100 Potenza, Italy

Abstract

The photochemical behaviour of furan, thiophene, pyrrole, isoxazole, imidazole, and pyrazole, and pyrazole derivatives appears to be very complex and, apparently, no common description of the reactivity of these heterocycles is possible. On the basis of PM3-RHF-Cl semiempirical calculations an unitary description of the behaviour of theses molecules can be made.

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Review | Special issue | Vol 50, No. 2, 1999, pp.1137-1156
Published online:
DOI: 10.3987/REV-98-SR(H)7
Diels-Alder Reactions of Benzo[b]furan-4,5-diones and Benzo[b]furan-4,7-diones

Pascal Nebois and Houda Fillion*

*Laboratoire de Chimie Organique, Institut des Sciences Pharmaceutiques et Biologiques, Université Claude Bernard, Lyon I, 8 avenue Rockfeller, 69373 Lyon Cedex 08, France

Abstract

The synthetic potentiality of benzofurandiones in Diels-Alder reactions is reported. Factors influencing the regiochemistry are discussed.

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Review | Special issue | Vol 50, No. 2, 1999, pp.1157-1211
Published online:
DOI: 10.3987/REV-98-SR(H)8
1-Hydroxyindoles

Masanori Somei*

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

Abstract

This review summarizes our hypotheses, syntheses, physical and chemical properties, and chemical reactions of 1-hydroxyindoles. Syntheses of natural products having 1-methoxyindole nucleus 1-methyoxy derivatives of indole alkaloids are also included. Application of the chemistry of 1-hydroxyindoles to the syntheses of biologically active substances, syntheses of tryptophan-4,5-diones and their reactions, and biological evaluation of 1-hydroxyindoles are reviewed.

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Review | Special issue | Vol 50, No. 2, 1999, pp.1213-1226
Published online:
DOI: 10.3987/REV-98-SR(H)10
1,3-Dipolar Cycloadditions of Five and Six Membered Cyclic Nitrones to α,β-Unsaturated Acid Derivatives

Pedro de March,* Marta Figueredo, and Josep Font

*Departament de Química, Universidad Autònoma de Barcelona, 08193 Bellaterra (Barcelona), Spain

Abstract

The cycloadditions of 3,4-dihydro-2H-pyrrole 1-oxide, 3,4,5,6-tetrahydropyridine 1-oxide, and (S)-3,4-dihydro-2-hydroxymethyl-2H-pyrrole 1-oxide to α,β-unsaturated acid derivatives have been reviewed. As Z-olefins, several five, six, and seven membered lactones with different functionalization at the γ-position were employed. As E-olefins, γ-hydroxy-, γ-alkoxy-, and γ-oxo-α,β-unsaturated esters have been incorporated to this study. Steric factors play a very important role in the regio- and stereochemical outcome of these 1,3-dipolar cycloadditions. cis-Olefins yield products derived mainly from an exo transition state, while the cycloadducts of trans-olefins result mainly from endo approaches.

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Review | Special issue | Vol 50, No. 2, 1999, pp.1227-1267
Published online:
DOI: 10.3987/REV-98-SR(H)11
Reactions of 1,4-Dichlorobut-2-yne Derivatives Leading to Heterocycles

Krishna C. Majumdar* and Paritosh Biswas

*Department of Chemistry, University of Kalyani, Kalyani-741 235, W. B., India

Abstract

This short review summarizes the syntheses of various types of chrom-3-ene derivatives by hydration of acetylenic linkage and polyheterocycles such as benzofuro[3,2-c]benzopyrans, benzofuro[3,2-b]benzofurans, benzofuro[2,3-b]benzofurans and a number of other heterocyclic systems by [3,3] sigmatropic rearrangements from 1,4-dichlorobut-2-yne derivatives.

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51 data found. 31 - 51 listedFirst Previous