Regular Issue

Vol. 38, No. 1, 1994

27 data found. 1 - 27 listed
Communication | Regular issue | Vol 38, No. 1, 1994, pp. 1 - 4
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DOI: 10.3987/COM-93-6467
Radical Cyclization of 1-Benzylisoquinoline-3-ones: A New Synthesis of the 4,5-Dioxoaporphine Pontevedrine

Juan C. Estévez, M. Carmen Villaverde, Ramón J. Estévez, and Luis Castedo*

*Departamento de Química Orgánica Universidad de Santiago, Secciòn de Alcaoids (C.S.I.C), E-15706, Santiago de Compostela, Spain


Tributyltin hydride induced intramolecular radical cyclization of 1-bromobenzylisoquinoline-3-one (1) allowed us to obtain the new 5-oxoaporphines (4 and 5), which were converted into the 4,5-dioxoaporphine pontevedrine (3b).

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Communication | Regular issue | Vol 38, No. 1, 1994, pp. 5 - 8
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DOI: 10.3987/COM-93-6523
Synthesis and Reactions of 3,4-dihydro-2H-1,4-benzoxazine Derivatives

Sambasivarao Kotha,* Vandana Bindra, and Atsuo Kuki*

*Department of Chemistry, Baker Laboratory, Cornell University, Ithaca, NY 14853-1301, U.S.A.


Several 3,4-dihydro-2H-1,4-benzoxazine derivatives were prepared from commercially available benzoxazoles by use of an efficient two step sequence. Aryl functionalization reactions allowing access to further benzoxazine derivatives are also described.

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Communication | Regular issue | Vol 38, No. 1, 1994, pp. 9 - 16
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DOI: 10.3987/COM-93-6531
Substituent Effects in Frontier Orbitals of Cyclic Hydroxamic Acids

Boris Weiss-López* and Héctor R. Bravo

*Departamento de Química, Facultad de Ciencias, Unversidad de Chile, Casilla 653, Santiago, Chile


AM1 full geometry optimization of seven substituted cyclic hydroxamic acids (Hx) was performed. A qualitative correlation between Elumo vs Hammett’s σp was observed. The reactivity of these 7-substituted Hx with hard nucleophiles seems to follow basic principles of frontier orbitals theory. Experimental support was obtained from the reaction of six Hx with 2-methoxyethylamine.

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Communication | Regular issue | Vol 38, No. 1, 1994, pp. 17 - 20
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DOI: 10.3987/COM-93-6544
A New Concise Approach to the Enantioselective Synthesis of the Hydroxyamino Acid Moiety of AI-77-B

Hiyoshizo Kotsuki,* Mitsuhiro Iwasaki, and Masamitsu Ochi

*Department of Chemistry, Faculty of Science, Kochi University, Kochi University


The hydroxyamino aicd moiety of AI-77-B has been prepared from D-ribose in an optically pure form via stereoselective alkylation of N-acylpyrrolidinium ion intermediates as the key step.

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Communication | Regular issue | Vol 38, No. 1, 1994, pp. 21 - 25
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DOI: 10.3987/COM-93-6548
A Convenient Synthesis of 2-Pyrazolines and Pyrazoles from Aldehyde Hydrazones and Ethyl Propiolate

Yasuhiro Kamitori, Masaru Hojo, Ryoichi Masuda,* Masaki Fujishiro, and Masaaki Wada

*Department of Industrial Chemistry, Faculty of Engineering, Kobe University, Rokkodai-cho, Nada-ku, Kobe 657-8501, Japan


Aldehyde methylhydrazones (3) reacted with ethyl propiolate in the presence of acetic acid affording 4-ethoxycarbonyl-1-methyl-2-pyrazolines (4) in 13 - 44% yields. Easily 4 was dehydrated to the corresponding pyrazoles (6) by treatment with H2O2 in the presence of FeCl2.

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Communication | Regular issue | Vol 38, No. 1, 1994, pp. 27 - 30
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DOI: 10.3987/COM-93-6551
Synthesis of 9-(C-5-Hydroxy-C-4-hydroxymethylcyclopent-2-en-R-1-yl)-9H-adenine [(±)-Epinor-BCA]

Akemi Toyota,* Nobuya Katagiri, and Chikara Kaneko

*Pharmaceutical Institute,Tohoku University,Aobayama, Sendai 980-8578, Japan


9-(c-5-Hydroxy-c-4-hydroxymethylcyclopent-2-en-r-1-yl)-9H-adenine [(±)-Epinor-BCA] has been synthesized from the bicyclic hydroxy lactone (2) in eleven steps.

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Communication | Regular issue | Vol 38, No. 1, 1994, pp. 31 - 34
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DOI: 10.3987/COM-93-6557
Intramolecular Diels-Alder Reaction of Benzynes: A Novel Strategy for the Construction of Tetrahydrobenzazepine Skeletons

Hiyoshizo Kotsuki,* Tadahiro Nobori, Toshihiro Asada, and Masamitsu Ochi

*Department of Chemistry, Faculty of Science, Kochi University, 2-5-1, Akebono-cho, Kochi 780-8520, Japan


Intramolecular Diels-Alder reaction of benzynes, generated from ortho-haloaniline derivatives by the action of lithium 2,2,6,6-tetramethylpiperidide, with furans has been developed as a novel route for the construction of tetrahydrobenzazepine skeletons.

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Communication | Regular issue | Vol 38, No. 1, 1994, pp. 35 - 39
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DOI: 10.3987/COM-93-6558
Synthesis and Stereospecific Fragmentation of 3-Thiabicyclo[3.1.0]hexane 3,3-Dioxides

Hsi-Hwa Tso,* Li-Hong Tseng, and Yu-Ying Yu

*Institutue of Chemistry, Academia Sinica, 128, Yan-Chiu-Yuan Road, Sec II, Nankang, Taipei,11529, Taiwan, R.O.C.


Synthesis of new stereoisomeric 3-thiabicyclo[3.1.0]hexane 3,3-dioxides and experimental proof of their fragamentation to 1,4-dienes by a concerted, disrotatory process are described.

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Communication | Regular issue | Vol 38, No. 1, 1994, pp. 41 - 44
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DOI: 10.3987/COM-93-6562
Regioselective Alkylation of 5-Substituted Benzosulfolenes. Some Comments for Its Regioselectivity

Ken Kanematsu,* Isao Kinoyama, Hitoshi Sato, Eiji Osawa,* Ok-Ja cha, and Toshiyuki Hata

*Institute of Synthetic Organic Chemistry, Faculty of Pharmaceutical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan


Direct alkylation of the 5-substituted benzosulfolenes gave exclusively 3-alkylated 5-substituted benzosulfolenes. The regioselectivity was discussed in terms of he frontier molecular orbital theory.

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Communication | Regular issue | Vol 38, No. 1, 1994, pp. 45 - 50
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DOI: 10.3987/COM-93-6563
A New Method for the Construction of Indole Nucleus

Masatomo Iwao

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


Directed lithiation of N-tert-butoxycarbonylanilines and subsequent reaction with 1-tert-butyldimethylsilyl-1-phenylsulfinylethene gave the conjugate addition products which, without isolation, were cyclized to 1-tert-butoxycarbonyl-2-phenylthioindolines under thermal sila-Pummerer reaction conditions.

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Communication | Regular issue | Vol 38, No. 1, 1994, pp. 51 - 54
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DOI: 10.3987/COM-93-6576
A Synthesis and Structural Confirmation of 3,5-Bis(2-alkylimidazol-4-yl)-1,2,4-trithiolanes

Kuniaki Tatsuta,* Shozo Miura, Naoki Kano, and Shigeo Fujita

*Graduate School of Science and Engineering, Waseda University, 3-4-1 Okubo, Shinjuku-ku, Tokyo 169-8555, Japan


The structures of the 4-formylimidazole equivalents which were prepared by heating 2-alkyl-4-dithiocarboxylimidazoles with 47% HBr or conc. H2SO4 have been revised to be 3,5-bis(2-alkylimidazol-4-yl)-1,2,4-trithiolanes by X-ray crystallographic analyses.

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Communication | Regular issue | Vol 38, No. 1, 1994, pp. 55 - 56
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DOI: 10.3987/COM-93-6580
Faveloxide, a New Isoprenoid Derivative from the Brazilian Plant, Cnidoscolus phyllacanthus

Tomihisa Ohta, Yuichi Endo, Rikako Kikuchi, and Shigeo Nozoe*

*Pharmaceutical Institute, Tohoku University, Aobayama, Sendai 980-8578, Japan


A new isoprenoid derivative, faveloxide, was isolated from the bark of Cnidoscolus phyllacanthus. The relative stereostructure (1) was determined on the basis of a spectroscopic analysis and a chemical transformation.

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Paper | Regular issue | Vol 38, No. 1, 1994, pp. 57 - 69
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DOI: 10.3987/COM-91-5873
Reactions of 5-(p-Anisyl)-2-methyl-7-(p-tolyl)-4H-pyrido[2,3-d][1,3]oxazin-4-one

Hassan M. F. Madkour,* Mounir A. I. Salem, Taha M. Abdel-Rahman, and Mohamed E. Azab

*Laboratory of Synthetic Organic Chemistry, Chemistry Department, Faculty of Science, Ain Shams University, Abbassiya 11566, Cairo, Egypt


5-(p-Anisyl)-2-methyl-7-(p-tolyl)-4H-pyrido[2,3-d][1,3]oxazin-4-one (III) was prepared. The reactivity of III towards nucleophilic reagents was investigated. 5-(p-Anisyl)-2-methyl-7-(p-tolyl)-4H-pyrido[2,3-d]pyrimidin-4-one(VI) was synthesised from III by the action of ammonium acetate and zinc chloride. The structure of VI was chemically confirmed by reactions with acetic anhydride, benzoyl chloride, chloroacetic acid, methyl iodide, dimethyl sulphate and ethyl bromoacetate. Compound (VI) reacted with secondary and primary amines under Mannich conditions to afford 5-(p-anisyl)-2-methyl-3-methylene substituted amino-7-(p-tolyl)-4H-pyrido[2,3-d]pyrimidin-4-ones (XIV) and (XV), respectively. Thiation of VI gave the thione 5-(p-anisyl)-2-methyl-7-(p-tolyl)-4H-pyrido[2,3-d]pyrimidin-4-thiones(XIX).

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Paper | Regular issue | Vol 38, No. 1, 1994, pp. 71 - 80
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DOI: 10.3987/COM-93-9462
A Synthesis of Pyrano[2,3-c]pyrroles from Cinnamoyloximinoacetonitrile

Galal A. M. Nawwar,* Randa H. Swellem, and Laila M. Chabaka

*Natural Products Department, National Research Centre, Dokki, Cairo, Egypt


An approach to the title ring system starting with the available cinnamoyloximinoacetonitrile (1) is proposed. It involves its reaction with various nucleophiles and subsequent addition of the resulting pyrrole derivatives (3,4) to 2-substituted cinnamonitriles (5), in a Micheal type reaction, thus affording the pyrano[2,3-c]pyrroles (6).

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Paper | Regular issue | Vol 38, No. 1, 1994, pp. 81 - 94
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DOI: 10.3987/COM-93-6515
Antitumor Agents. VI. Synthesis and Antitumor Activity of Ring A-, Ring B-, and Ring C-Modified Derivatives of Camptothecin

Masamichi Sugimori, Akio Ejima, Satoru Ohsuki, Kensuke Matsumoto, Yasuyoshi Kawato, Megumi Yasuoka, Hiroaki Tagawa, and Hirofumi Terasawa*

*Exploratory Research Laboratories, Daiichi Pharmaceutical Co., Ltd., 16-13, Kitakasai 1-chome, Edogawa-ku, Tokyo 134, Japan


Eleven ring A-, ring B-, and ring C-modified analogues of the antitumor alklaoid camptothecin (1) were prepared and evaluated for cytotoxicity and antitumor activity against P388 mouse leukemia. Among the six ring A-modified analogues, hexacyclic compound (14) retained the same order of activity as 1. Most of the ring B- and ring C-modified analogues displayed greatly reduced activity, whereas compound (39), which has an alkylidene group at position 5, was found to be as active as 1. These results confirmed the necessity of the intact rings A, B, and C of 1 for antitumor activity. Further, the higher activity of 14 and 39 suggest that the "northern" part of the camptothecin molecule may be a suitable site for functionalization to obtain more potent analogues of 1.

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Paper | Regular issue | Vol 38, No. 1, 1994, pp. 95 - 102
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DOI: 10.3987/COM-93-6516
Synthesis of Diethyl 1,2,3-Triazolealkylphosphonates through 1,3-Dipolar Cycloaddition of Azides with Acetylenes

Francisco Palacios,* Ana Ma Ochoa de Retana, and Jaione Pagalday

*Departamento de Química Orgánica I, Facultad de Farmacia , Universidad del País Vasco, Apartado 450, 01007 Vitoria, Spain


4,5-Disubstituted 1-(diethoxyphosphorylmethyl)-1,2,3-triazoles were prepared through thermal 1,3-dipolar cycloaddition of diethyl azidoalkylphosphonates with alkynes.

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Paper | Regular issue | Vol 38, No. 1, 1994, pp. 103 - 111
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DOI: 10.3987/COM-93-6520
Synthesis of 2-Substituted 2,3-Dihydro-9-phenyl-1H-pyrrolo[3,4-b]quinolin-3-ones as Potential Peripheral Benzodiazepine-Receptor Ligands

Maurizio Anzini, Andrea Cappelli,* and Salvatore Vomero

*Dipartimento Farmaco Chimico Technlogico, Università degli Studi di Siena, Banchi di Sotto, 55 - 53100 Siena, Italy


Two synthetic routes to the achievement of the title compounds are described. 2-Chloromethyl-3-ethoxycarbonyl-4-phenylquinoline (4) was transformed into the corresponding lacton (5) which in two setps was converted into its isomeric lacton (7). Aminolysis of 7 gave γ-hydroxyamide (8) which was in turn transformed into γ-chloroamide (9). Cyclization of 9 with sodium hydride in presence of oxygen led to the oxidized compound (10), while by carrying out the cyclization reaction under inert atomosphere, 2-benzyl-2,3-dihydro-9-phenyl-1H-pyrrolo[3,4-b]quinolin-3-one (3a) was obtained. Autoxidation of anion at 1-position of compound (3a) was considered to account for these results and a mechanistical interpretation was given. A simplier and more versatile route to obtain the title compounds was also developed.

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Paper | Regular issue | Vol 38, No. 1, 1994, pp. 113 - 123
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DOI: 10.3987/COM-93-6538
Synthesis of Nitrogen Heterocycles from 1-Methylthio-2-phenyl-2-azabuta-1,3-diene-4,4-dicarbonitriles

Antonio Lorente,* Pedro Gámez, and María del Mar Contreras

*Departamento de Química Orgánica, Universidad de Alcalá de Henares, 28871 Alcalá de Henares (Madrid), Spain


The reactions of tittle compounds with different nucleophiles afforded a simple method for a synthesis of pyrimidines, 1,2,4-triazoles, 1,2,4-oxadiazoles and 1,3,5-triazines

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Paper | Regular issue | Vol 38, No. 1, 1994, pp. 125 - 134
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DOI: 10.3987/COM-93-6541
Pyridazines, 69. 2-Fluorophenyl 3-Pyridazinyl Ketone as a Versatile Precursor for Benzo-annelated Heterocyclic Systems

Norbert Haider, Gottfried Heinisch,* and Jöran Moshuber

*Institute of Pharmaceutical Chemistry, University of Innsbruck, Innrain 52a, A-6020 Innsbruck, Austria


The fluorophenyl pyridazinyl ketone (4), conveniently prepared from 3,6-dichloropyridazine, was shown to be a valuable precursor for so far not accessible pyridazinyl-substituted benzo-annelated five-, six, or seven-membered heterocycles (9,11,6a,b) and for the two novel diazaacridones (12) and (13).

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Paper | Regular issue | Vol 38, No. 1, 1994, pp. 135 - 142
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DOI: 10.3987/COM-93-6543
Improved Labelling Methods for C9-2H-Retronecine

Jeannette T. Hovermale, Fraser F. Fleming, James D. White, and A. Morrie Craig*

*College of Veterinary Medicine, Oregon State University, Gilbert Hall 153, Corvallis Oregon 97331, U.S.A.


The necine base retronecine (1a), common to numerous toxic pyrrolizidine alkaloids, has previously been labelled with 3H at C-9 for use in metabolic studies. The current method for labelling retronecine is inefficient, and we report here an improved method of which utilizes the Dess-Martin periodinane reagent. Characterization of the resulting aldehyde (2) is described. The overall yield of C9-2H-retronecine (1b) is 71% (from 1a).

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Paper | Regular issue | Vol 38, No. 1, 1994, pp. 143 - 149
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DOI: 10.3987/COM-93-6546
A One-Pot synthesis of Substituted Thieno[3,2-b]thiophenens and Selenolo[3,2-b]selenophenes

Keun Soo Choi, Kanji Sawada, Haibiao Dong, Masamatsu Hoshino, and Juzo Nakayama*

*Department of Chemistry, Faculty of Science, Saitama University, Saitama, Saitama 338-8570, Japan


Heating a mixture of 2,5-dimethyl-3-hexyne-2,5-diol (3a) with elemental sulfur in benzene at 190-200 °C in an autoclave affords 3,6-dimethylthieno[3,2-b]thiophene (5a) in 26% yield. The reaction provides a practical one-pot synthesis of several gram quantities of 5a, even if the yield is moderate, since 3a is commercially available and inexpensive. The reaction proceeds via 2,5-dimethyl-1,5-hexadiene-3-yne (4a) as one of probable intermediates, which is produced by dehydration of 3a. Addition of p-toluenesulfonic acid promotes the dehydration of 3a and thus can lower the reaction temperature. In addition, the reaction of 4a, prepared from 3a independently, with sulfur affords 5a in a somewhat improved yield (33%). The reaction of 3a with elemental selenium also provides a one-pot synthesis of 3,6-dimethylselenolo[3,2-b]selenophene (9a) in 16% yield. Reactions of some other acetylenic diols with elemental sulfur and selenium are also described.

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Paper | Regular issue | Vol 38, No. 1, 1994, pp. 151 - 158
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DOI: 10.3987/COM-93-6547
Biologically Active Xenicane Diterpenoids from the Gorgonian Acalycigorgia Sp.

Masamitsu Ochi,* Kumi Kataoka, Akira Tatsukawa, Hiyoshizo Kotsuki, and Kozo Shibata*

*Faculty of Science, Kochi University, 2-5-1, Akebono-cho, Kochi 780-8520, Japan


Five new biologically active diterpenoids, acalycigorgins A-E, have been isolated from the gorgonian Acalycigorgia sp. The structures and relative stereochemistry of acalycigorgins were determined by extensive 2D-nmr studies.

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Paper | Regular issue | Vol 38, No. 1, 1994, pp. 159 - 166
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DOI: 10.3987/COM-93-6549
A Convenient New Synthesis of 6- and 7-Azaestrane Lactams and Their N-Chloro Derivatives

Thomas G. Back* and Joseph H.-L. Chau

*Department of Chemistry, University of Calgary, Calgary, Alberta, T2N 1N4, Canada


17β-Acetoxy-3-methoxy-6-azaestra-1,3,5(10)-trien-7-one and 17β-acetoxy-3-methoxy-7-azaestra-1,3,5(10)-trien-6-oen, and their N-chloro derivatives were prepared from 3-methoxyestrone.

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Paper | Regular issue | Vol 38, No. 1, 1994, pp. 167 - 175
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DOI: 10.3987/COM-93-6550
A New Hydrolyzable Tannin from Geum japonicum and Its Antiviral Activity

Hong-Xi Xu, Shigetoshi Kadota,* Hua Wang, Masahiko Kurokawa, Kimiyasu Shiraki, Takao Matsumoto, and Tsuneo Namba

*Department of Virology, Faculty of Medicine, Toyama Medical and Pharmaceutical University, 2630 Sugitani, Toyama, Toyama 930-0194, Japan


A new hydrolyzable tannin, geponin, in addition to six known compounds were isolated from the aqueous extract of whole plant of Geum japonicum and their structures were determined by the use of 2D nmr. Geponin and gallic aldehyde showed potent antiviral activity against HSV-1 among the isolated seven compounds. These may contribute antiviral activity of the aqueous extract of G. japonicum.

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Paper | Regular issue | Vol 38, No. 1, 1994, pp. 177 - 179
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DOI: 10.3987/COM-93-6552
One-Pot Route to Vinyl-2,3-dihydrobenzofurans

Lajos Novák, Péter Kovács, Pál Kolonits, and Csaba Szántay*

*Institute for Organic Chemistry, Technical University Budapest, H-1111 Budapest, P.O. Box 91Gellért tér 4, Hungary


A one-pot approach to the title compounds (5) and (7) has been developed by employing 1,3- and 3,3-rearrangements of in situ generated allyl aryl ethers followed by cyclization.

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Paper | Regular issue | Vol 38, No. 1, 1994, pp. 181 - 187
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DOI: 10.3987/COM-93-6559
7-Hydroxypleurocorine, a New Alkaloid Isolated from Pleurostylia opposita

Corinne Séguineau, Pascal Richomme,* Jean Bruneton, and Peter Meadows

*CEPM, UFR des Sciences Médicals et de Pharmaceutiques, Université d’Angers, 16, Boulevard Daviers, 49045 Angers, France


7-Hydroxypleurocorine (1), a novel spermidine alkaloid was isolated from the leaves of Pleurostylia opposita and its structure was elucidated by means of extensive 1H and 13C nmr studies involving DQF COSY, HOHAHA, HMBC and HMQC experiments. The relative stereochemistry of the molecule was also probed using NOE difference spectroscopy. 7-Hydroxypleurocorine represents a new type of spermidine derivative including a pyrrolidinone.

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Paper | Regular issue | Vol 38, No. 1, 1994, pp. 189 - 196
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DOI: 10.3987/COM-93-6571
Synthesis of Na-Boc-5β-cyano-defornyl-E-geissoschizine: A Potential Synthon in the Preparation of Sarpagan and Ajmalan Ring Systems

Reija Jokela, Minna Halonen, and Mauri Lounasmaa*

*Laboratory for Organic and Bioorganic Chemistry, Technical University of Helsinki, P.O. Box 6100, FIN-02150 HUT Espoo 15, Finland


The paper describes a short, synthetic route to Na-Boc-5β-cyano-deformyl-E-geissoschizine (8), a prototype of potential synthons in the preparation of sarpagan and ajmalan ring systems.

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27 data found. 1 - 27 listed