Regular Issue

Vol. 57, No. 7, 2002

19 data found. 1 - 19 listed
Communication | Regular issue | Vol 57, No. 7, 2002, pp. 1211 - 1217
Published online:
DOI: 10.3987/COM-02-9479
Effects of Base, Electrophile, and Substrate on the Selective Alkylation of Heteroaromatic Systems

Thomas E. Smith,* Michelle S. Mourad, and Alan J. Velander

*Department of Chemistry, Williams College, 47 Lab Campus Drive, Williamstown, MA 01267-2692, U.S.A.


Several heteroaromatic systems, including oxazoles, pyrazoles, and thiophenes, are regioselectively alkylated using lithium diethylamide. Effects of substrate, base, and electrophile on the selectivity of this process are surveyed and interpreted.

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Communication | Regular issue | Vol 57, No. 7, 2002, pp. 1219 - 1225
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DOI: 10.3987/COM-02-9480
Synthetic Studies toward Hennoxazole A. Use of a Selective Bisoxazole Alkylation as the Key Fragment Coupling

Thomas E. Smith* and Emily P. Balskus

*Department of Chemistry, Williams College, 47 Lab Campus Drive, Williamstown, MA 01267-2692, U.S.A.


A model system for side chain fragment coupling to the core of hennoxazole A is investigated. Lateral metallation of a C13-TBS-protected bisoxazole, using lithium diethylamide, allows for selective and efficient alkylation at C15.

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Communication | Regular issue | Vol 57, No. 7, 2002, pp. 1227 - 1230
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DOI: 10.3987/COM-02-9497
Selective Protection of 5-Aminobenzotriazole for Controlled Reaction at the Primary Amine

Denise McKeown, Callum J. McHugh, Ailie McCabe, W. Ewen Smith, and Duncan Graham*

*Department of Pure and Applied Chemistry, University of Strathclyde, 295 Catheral Street, Glasgow G1 1XL, U.K.


The selective protection of the triazole function of 5-aminobenzotriazole is reported. Two different protecting groups were used to prevent side reactions through the triazole amine acting as a leaving group when 5-aminobenzotriazole was used as a nucleophile. This allowed the addition of aminobenzotriazole to two target molecules to impart metal complexing properties to the new species.

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Communication | Regular issue | Vol 57, No. 7, 2002, pp. 1231 - 1234
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DOI: 10.3987/COM-02-9503
Reactions of 1-Methoxy-3-(2-nitrovinyl)indole with Nucleophiles: An Interesting Solvent Effect and a Novel Preparation of 3-Substituted 1-Methoxyindoles

Koji Yamada, Fumio Yamada, and Masanori Somei*

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


Nucleophiles react with 1-methoxy-3-(2-nitrovinyl)indole (3) at the 2-position regioselectively in a dipolar aprotic solvent (DMF or HMPA), while in THF they undergo Michael addition to the β-carbon of nitrovinyl side chain. Depending on bases employed, the resultant Michael addition products (6d, 10, and 11) are found to undergo interesting cyclizations to give novel 3-substituted 1-methoxyindoles (7, 9, and 12).

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Communication | Regular issue | Vol 57, No. 7, 2002, pp. 1235 - 1238
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DOI: 10.3987/COM-02-9512
Preparatory Study for the Synthesis of the Marine Sponge Alkaloids Asmarines A-F: Synthesis of Their Heterocyclic Portions

Masashi Ohba* and Takahiro Tashiro

*Center for Instrumental Analysis, Kanazawa University, 13-1 Takara-machi, Kanazawa 920-0934, Japan


A synthesis of three tricyclic compounds (1c), (2c), and (3c), selected as models for the heterocyclic portions of the marine sponge alkaloids asmarines A—F, has been accomplished through cyclization of the 7-alkyl-6-chloropurine derivatives.

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Communication | Regular issue | Vol 57, No. 7, 2002, pp. 1239 - 1245
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DOI: 10.3987/COM-02-9515
Photo-stimulated Heterolysis of the C(=O)-O Bond in (Z)-N-Acetyl-α-dehydrophenylalanine Aryl Ester Derivatives

Hideki Hoshina, Kentaro Nakayama,Tetsutaro Igarashi, and Tadamitsu Sakurai*

*Departmnet of Applied Chemistry, Faculty of Engineering, Kanagawa University, 3-27-1 Rokkakubashi, Kanagawa-ku, Yokohama 221-8686, Japan


The irradiation of the title compounds [(Z)-1] in acetonitrile was found to give (Z)-2-methyl-4-(4-chlorobenzylidene)-5(4H)-oxazolone [(Z)-2] and phenols or naphthols (3), along with minor amounts of the Fries-rearranged products (4) and (E)-2. Solvent and substituent effects on the product distribution confirmed that the heterolytic cleavage of the ester C(=O)—O bond of the starting 1 in the excited singlet state is responsible for appearance of both 2 and 3 whereas 4 is derived from the homolysis (of the ester bond) taking place in competition with the predominant heterolysis of this bond. It was suggested that there is a pronounced contribution of charge transfer from the aryloxy oxygen to the parent π system in the excited singlet state.

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Paper | Regular issue | Vol 57, No. 7, 2002, pp. 1247 - 1256
Published online:
DOI: 10.3987/COM-02-9488
Effect of the N6-Methyl Group on Adenine Ring on the Intramolecular Base-Pairing of Adenine with Thymine in Various Solvents

Toshio Itahara*

*Department of Bioengineering, Faculty of Engineering, Kagoshima University, Korimoto, Kagoshima 890-0065, Japan


In order to study an intramolecular hydrogen bond between the adenine and thymine rings of 9-[12-(thymin-1- yl)dodecyl]adenine and N6-methyl-9-[12-(thymin-1-yl)- dodecyl]adenine, their NMR chemical shifts of NH of thymine ring at 3-position were compared with those of N6,N6-dimethyl-9-[12-(thymin-1-yl)dodecyl]adenine in various solvents. The thermodynamic parameters of the intramolecular hydrogen bond in chloroform and benzene were estimated. The hydrogen bond was confirmed by the IR spectroscopy.

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Paper | Regular issue | Vol 57, No. 7, 2002, pp. 1257 - 1264
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DOI: 10.3987/COM-02-9490
A New Synthesis of 1,2-Diazetines via Simple Cycloacylation Reactions

Daniela Pufky, Rainer Beckert,* Manfred Döring, and Olaf Walter

*Institute for Organic and Macromolecular Chemistry, Friedrich Schiller University Jena, D-07743 Jena, Lessingstr. 8, Germany


Several new 1,2-diazetines (4a-e) were synthesized via simple cycloacylation reactions of various monoalkylhydrazines (5a-c) with bis-imidoyl chlorides of oxalic acid (1). An X-Ray crystal structure analysis obtained from single crystals of 4a reveals an additional double bond in the 4-membered ring system. Treatment of these heterocycles with strong bases formed delocalized anions (6) which can be methylated giving 1,2-disubstituted diazetidines (7a,b). Alternatively, the latter derivatives can be synthesized via a cycloacylation employing 1,2-dimethylhydrazine and bis-electrophiles (1).

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Note | Regular issue | Vol 57, No. 7, 2002, pp. 1265 - 1272
Published online:
DOI: 10.3987/COM-02-9466
Anti HSV-1 Alkaloids from a Feeding Deterrent Marine Sponge of the Genus Aaptos

Angelica F. Coutinho, Brian Chanas, Thiago M. L. e Souza, Izabel C. P. P. Frugrulhetti, and Rosângela de A. Epifanio*

*Departamento de Química Organica, Instituto de Qímica, Universidade Federal Fluminense , Quteiro S. João Batista s/n, Valonguinho, Centro, Niterói, Rio de Janeiro, 24020-150, Brazil


The crude extract from the marine sponge Aaptos sp. collected in Abrolhos, Bahia, Brazil, was unpalatable to a natural assemblage of reef fishes. Preliminary assays also indicated the presence of anti HSV-1 compounds in this crude mixture. Successive chromatographic purification afforded a new alkaloid, 8,9-dimethoxy-4-methyl-4H-benzo[de][1,6]naphthyridine (2,4-methylaaptamine) and the known demethyloxyaaptamine (1), which structures were determined mainly by 1D and 2D NMR. Both compounds showed potent antiviral activity against herpes simplex virus type 1 and low toxicity to Vero cells, suggesting that they may be selectively targets to inhibit virus replication.

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Note | Regular issue | Vol 57, No. 7, 2002, pp. 1273 - 1278
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DOI: 10.3987/COM-02-9477
Oxidative Coupling of Indoline-2-thione or Oxindole: Formation of Cyclic and Acyclic Indole Trimers

Tomasz Janosik and Jan Bergman*

*Unit for Organic Chemistry, Department of Biosciences at Novum, Karolinska Institutet, Novum Research Park, SE-141 57 Huddinge, Sweden


Oxidation of indoline-2-thione using p-toluenesulfonyl azide produced a modest yield of the structurally novel cyclic sulfur containing indole trimer (12). In contrast, the oxidation of oxindole with iodine instead produced an acyclic trimeric indole derivative.

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Note | Regular issue | Vol 57, No. 7, 2002, pp. 1279 - 1286
Published online:
DOI: 10.3987/COM-02-9482
5-(3-Quinolinylthio)methyl-tetrahydro-2-furanones from 3,3’-Bis(4-substituted quinolinyl) Disulfides

Krzysztof Marciniec, Andrzej Maslankiewicz,* and Stanislaw Boryczka

*Department of Organic Chemistry, The Medical University of Silesia, Jagiellonska Str. 4, 41-200 Sosnowiec, Poland


The intramolecular lactonization of 4-pentenoic acid to the title tetrahydrofuranones (12) was performed by addition of electrochemically generated sulfenyl cations starting from 3,3’-bis(4-substituted quinolinyl) disulfides (7a, b, c, d, e) and 3,3’-bis(1-methyl-1,4-dihydro-4-oxo-quinolinyl) disulfide (9b) and using bromide as a redox catalyst. Two syntheses of diquinolinyl disulfideÅ@(7e) were described as well.

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Note | Regular issue | Vol 57, No. 7, 2002, pp. 1287 - 1292
Published online:
DOI: 10.3987/COM-02-9483
Two New Pyranoflavanones from the Stems Derris reticulata

Chulabhorn Mahidol, Hunsa Prawat, Wirongrong Kaweetripob, and Somsak Ruchirawat*

*Laboratory of Medicinal Chemistry, Chulabhorn Reseach Institute, Vipavadee-Rangsit Highway, Bangkok 10210, Thailand


Two new flavonoids, 4’,5-dihydroxy-8-hydroxymethyl-6’’,6’’-dimethylpyrano[2’’,3’’:7,6]flavanone (1), and 2’’,3’’-dihydroxylupinifolin (2) were isolated from the stems of Derris reticulata. Both compounds showed cytotoxic activity in the P-388 cell line. The structures were established by spectroscopic analysis and chemical transformations. The biosynthetic origin and the mechanism of formation of the hydroxymethyl group in compound (1) are proposed.

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Note | Regular issue | Vol 57, No. 7, 2002, pp. 1293 - 1297
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DOI: 10.3987/COM-02-9486
Syntheses of 3-Acylindoles via the Alkylation of the Dianion of 3-Acetylindole

Jeffrey H. Byers* and Yong Zhang

*Department of Chemistry and Biochemistry, Middlebury College, Middlebury, VT 05753, U.S.A.


The dianion of 3-acetylindole can be generated upon sequential treatment with NaH and n-BuLi. This dianion can be C-alkylated at the acetyl methyl group with high regioselectivity, leading to efficient syntheses of 3-acylindoles. Addition of excess electrophile leads to a dialkylated product.

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Note | Regular issue | Vol 57, No. 7, 2002, pp. 1299 - 1302
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DOI: 10.3987/COM-02-9493
Rapid Synthesis of Acridines Using Microwave

Hideko Koshima* and Kosuke Kutsunai

*Department of Applied Chemistry, Faculty of Engineering, Ehime University, 3 Bunkyo-cho, Matsuyama, 790-8577 Ehime, Japan


Microwave irradiation for several minutes caused reaction of diarylamines with carboxylic acids in the presence of zinc chloride to give 9-substituted acridines in good yield.

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Note | Regular issue | Vol 57, No. 7, 2002, pp. 1303 - 1311
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DOI: 10.3987/COM-02-9494
Pyrrolizine and Indolizine Derivatives from 1,6-Dioxo-2,4-diene by Inter- and Intramolecular Ring Closure

Chi Wi Ong,* Ming Chih Lai, Jing Jyh Jan, and Yu An Chang

*Department of Chemistry, National Sun Yat Sen University, Kaohsiung, 804, Taiwan, R.O.C.


A variety of 1-amino-alkyl esters and nitriles react with 1,6-dioxo-2,4-diene to give pyrrole derivatives in good yield. Mild basic conditions facilitate the further intramoleular Dieckmann or Thorpe like condensation giving pyrrolizine and indolizine derivatives. These reactions provide simple, two step sequence to pyrrolizine and indolizine derivatives with control of product dictated by the base used for the condensation reaction.

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Note | Regular issue | Vol 57, No. 7, 2002, pp. 1313 - 1318
Published online:
DOI: 10.3987/COM-02-9495
Reaction of Lithiotrimethylsilyldiazomethane with α-Oxoketene Dithioacetals

Rina Miyabe, Takayuki Shioiri, and Toyohiko Aoyama*

*Faculty of Pharmaceutical Sciences, Nagoya City University, Tanabe-dori, Mizuho-ku, Nagoya 467-8603, Japan


Reaction of lithiotrimethylsilyldiazomethane with α-oxoketene dithioacetals affords thiophenes, homologous ketones , and homologous alkynes depending upon substrates used.

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Note | Regular issue | Vol 57, No. 7, 2002, pp. 1319 - 1326
Published online:
DOI: 10.3987/COM-02-9496
Synthesis and Anticoccidial Activity of Some Azacyclo Organoborinates

Hitoshi Tabuchi, Harumoto Kawaguchi, Hisashi Taniguchi, Hideyuki Imazaki, and Yoshio Hayase*

*Nitto Kasei Co., ltd., 3-17-14 Nishiawaji, Higashiyodogawa-ku, Osaka City 533-0031, Japan


A series of azacyclo organoborinates derivatives of piperidinyl and pyridinyl alcohols were prepared and their anticoccidial activity was tested in vitro assay system. Among them, di(4-chlorophenyl)(2-piperidinylmethoxy-O,N)boron, di(3-trifluoromethylphenyl)( 2-piperidinylmethoxy-O,N)boron, di(3-trifluoromethylphenyl)(2-pyridinylmethoxy-O,N)boron, and di(3-trifluoromethylphenyl)(2-pyridinylethoxy-O,N)boron, showed moderate anticoccidial activity against Eimeria tenella.

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Review | Regular issue | Vol 57, No. 7, 2002, pp. 1327 - 1352
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DOI: 10.3987/REV-01-542
Syntheses of (-)-Physostigmine, with Particular Emphasis upon the Clarification of Two Enigmatic Early Synthetic Approaches

Brian Robinson

*Millhaven, Tideswell Lane, Eyam, Derbyshire, S32 5RD, U.K.


Following a synopsis of the studies whereby the structure, including absolute configuration, of (-)-physostigmine - a metabolite from diverse botanical and also microbial sources - was established, the pharmacology and clinical uses of the alkaloid, its enantiomer and its hydrolysis product, (-)-eseroline, are briefly but comprehensively discussed. Synthetic approaches to (-)-physostigmine and its 1,2,3,3a,8,8a-hexahydro-3a-methylpyrrolo[2,3-b]indole ring system are then considered, with particular emphasis upon the early endeavors in this area by three independent groups and the interpretation of the results obtained by one of them.

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Review | Regular issue | Vol 57, No. 7, 2002, pp. 1353 - 1365
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DOI: 10.3987/REV-02-549
Methods for Preparation of γ- and δ-Oxoacids as Useful Synthons for Heterocycles

Ferenc Csende and Géza Stájer*

*Institute of Pharmaceutical Chemistry, University of Szeged, POB 121, H-6720 Szeged, Eötvös u. 6, Hungary


Numerous synthetic routes have been recommended for the preparation of γ- and δ-oxo acids. The present paper collects methods which need simple starting materials, procedures and conditions. Many examples are presented, comparing the preparations of aliphatic, cycloalkane, aromatic and hetero ring-containing oxo acids from the aspects of yield, regio- and diastereoselectivity.

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19 data found. 1 - 19 listed