Regular Issue

Vol. 36, No. 2, 1993

16 data found. 1 - 16 listed
Communication | Regular issue | Vol 36, No. 2, 1993, pp. 219 - 222
Published online:
DOI: 10.3987/COM-92-6189
A Convenient Synthesis of 1-Aryl- and 1-Alkyl-1,4,5,6-tetrahydropyridazin-3(2H)-ones

Ki-Jun Hwang* and Kyung-Ho Park

*Korea Research Institute of Chemical Technology, Daeduk-Science Town, Daejoen 305-606, Korea


Aryl- and alkylhydrazines react with readily availalbe cyclopropanedicarboxylate (2) in refluxing acetonitrile to afford the corresponding 1-substituted 1,4,5,6-tetrahydropyridazin-3(2H)-ones (5) directly via nitrogen-carbon bond formation, cyclization and decarboxlylation of the cyclized intermediates.

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Communication | Regular issue | Vol 36, No. 2, 1993, pp. 223 - 229
Published online:
DOI: 10.3987/COM-92-6196
The Reaction of Unsaturated Carbonyl Compounds with "Activated" Sulfur

Ugo Chiacchio, Antonino Corsaro, Antonio Rescifina, Maria Gabriella Testa, and Giovanni Purrello*

*Dipartimento di Scienze Chimiche, Università di Catania, Viale A. Doria 6, 95125 Catania, Italy


In a reinvestigation of the sulfuration reaction of cinnamylideneacetophenone (1) with sulfur and triethylamine at room temperature, new products 6-benzoyl-3-phenyl-1,2-dithiolo[4,3-c]-1,2-dithiole (5), 6-benzoyl-3-phenyl-1,2-dithiine (6) and 5-benzoyl-3-benzylidene-1,2-dithiole (7) were obtained along with the known products 5-phenacylidene-3-phenyl-1,2-dithiole (2) and 5-benzoyl-2-phenylthiophene (3). The reaction of dibenzylideneacetone (8) under the same conditions affords thiopyran-4-one (9). By adding Lawesson reagent to the reactant mixtures of 1 and 8, a trithiapentalene derivative (4) was also formed.

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Communication | Regular issue | Vol 36, No. 2, 1993, pp. 231 - 235
Published online:
DOI: 10.3987/COM-92-6201
Alkylation and Convalent Adduct Formation of 2-Oxopurine

Adolf Gogoll, Lise-Lotte Gundersen, Frode Rise,* and Mats Valli

*Department of Chemistry, University of Oslo, P.O.Box 1033, Blindern, N-0315 Oslo, Norway


2-Oxopurine reacted with benzyl bromide and ethanol to give the covalent adduct 1,3,7-tribenzyl-6-ethoxy-2-oxopurine, as well as dibenzylated products. Carbon-carbon bond formation was observed in the reaction between 2-oxopurine, dry silica gel, and benzyl bromide, giving rise to 6-hydroxy-1,3,8-tribenzyl-2-oxopurine.

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Communication | Regular issue | Vol 36, No. 2, 1993, pp. 237 - 242
Published online:
DOI: 10.3987/COM-92-6214
1-Deaza-2’-deoxyadenosine: Phosphonate and Phosphoramidite Building Blocks for Solid-Phase Oligonucleotide Synthesis

Frank Seela* and Thomas Wenzel

*Laboratorium für Organische und Bioorganische Chemie, Institut für Chemie, Universität Osnabrück, Barbarastr. 7, D-4500 Osnabrück, Germany


The synthesis of the 3’-[(2-cyanoethyl)diisopropylphosphoramidite] (3b) and the 3’-phosphonate (3a) of 1-deaza-2’-deoxyadenosine (1b) is described. For this purpose compound 1b was protected at the 6-amino group with a benzoyl residue. Ensuing 4,4’-dimehoxytritylation of 1b and phosphitylation afforded the P(III) derivatives (3a) and (3b). They were successfully employed in solid-phase oligodeoxyribonucleotide synthesis of d(c1A-c1A-c1 A-A-A-A) (6). 13C-Nmr and 15N-nmr spectra of the compounds (1-5) are discussed.

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Communication | Regular issue | Vol 36, No. 2, 1993, pp. 243 - 247
Published online:
DOI: 10.3987/COM-92-6222
Chemical Modification of Erythromycins. XI. Synthesis of Clarithromycin (6-O-Methylerythromycin A) via Erythromycin A Quaternary Ammonium Salt Derivative

Yoshiaki Watanabe,* Masato Kashimura, Toshifumi Asaka, Takashi Adachi, and Shigeo Morimoto

*Research Center, Taisho Pharmaceutical Co., Ltd., 1-403 Yoshino-Cho, Ohmiya, Saitama 330-8530, Japan


Synthesis of clarithromycin via quaternary ammonium salt of erythromycin A, 2’-O-benzyl-3’-[benzyl(dimethyl)ammonio)-3’-de(dimethylamino)erythromycin A bromide 9-O-(benzyloxime) (2), was reported. Clarithromycin was obtained in 53% overall yield from erythromycin A 9-oxime (1).

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Communication | Regular issue | Vol 36, No. 2, 1993, pp. 249 - 252
Published online:
DOI: 10.3987/COM-92-6226
A Novel Rearrangement of N-Cyanomethylhydroxytetrahydroisoquinolinium Methiodides under Basic Conditions

Hiroshi Hara,* Masaki Endoh, Ken-ichi Kaneko, and Osamu Hoshino*

*Faculty of Pharmaceutical Sciences, Science University of Tokyo, 12, Ichigaya Funagawara-machi, Shinjuku-ku, Tokyo 162-0826, Japan


Reaction of N-cyanomethylisoquinolinium methiodide (2a) with sodium methoxide gave a rearranged tetrahydroisoquinolin-8-ol (5a) in high yield. With 1- or 4-substituted N-cyanomethylisoquinolinium (2b-d) and 8-hydroxytetrahydroisoquinolinium methiodides (2f), similar rearrangement was observed. Plausible mechanism on formation of the products was discussed.

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Communication | Regular issue | Vol 36, No. 2, 1993, pp. 253 - 257
Published online:
DOI: 10.3987/COM-92-6234
An One-Pot Synthesis of 5,11-Ethenoisoxazolo[5’’’,4’’’:3’,4’]furo[2’’,3’’:7’,8’]naphtho[2’,3’:4,5]furo[3,4-d]isoxazoles from 2-Isoxazoline-2-oxides

Kazuho Harada,* Kuniaki Sasaki, Eisuke Kaji, and Shonosuke Zen

*School of Pharmaceutical Sciences, Kitasato University, Shirokane, Minato-ku, Tokyo 108-8641, Japan


4-Aryl-3,5-bis(methoxycarbonyl)-2-isoxazoline-2-oxides were allowed to react with titanium tetrachloride by one-pot synthesis to afford novel fused heterocycles, 5,11-ethenoisoxazolo[5’’’,4’’’:3’,4’]furo[2’’,3’’:7’,8’]naphtho[2’,3’:4,5]furo[3,4-d]isoxazoles, which were also formed by stepwise synthesis via Diels-Alder dimerization of 3a,4-dihydro-5a,H-benzofuro[3,3a-d]isoxazoles attainable from the above isoxazoline-2-oxides. The structure determination of the dimer by single crystal X-ray analysis is reported.

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Paper | Regular issue | Vol 36, No. 2, 1993, pp. 259 - 280
Published online:
DOI: 10.3987/COM-92-6008
Addition Reactions of 5-Aminobenzotriazoles with Dimethyl Acetylenedicarboxylate (DMAD). Formation of (Z/E) Michael Adducts, (Benzotriazol-5-yl)-2-pyridones, a Triazolo-9,10-dihydrobenzo[b]azepine and a Triazolo-2-oxindole

Paolo Sanna, Antonio Nuvole, Piera Attilia Sequi, and Giuseppe Paglietti*

*Instituto di Chimica Farmaceutica, University of Sassari, Via Muroni 23/a, 07100 Sassari, Italy


5-Aminobenzotriazoles (1a-d) reacted with DMAD to give the regioselective Michael adducts (Z)-(2a-d), accompanied with (benzotriazol-5-yl)-2-pyridones (3b-d), and in one case (2c) with the triazolo-9,10-dihydrobenzo[b]azepine (4). Cyclisation of the adducts (Z)-(2b-d) in Dowtherm gave the triazolo[4,5-f]quinolinones (6b-d), which were converted into chloro derivatives (9b-d), in trun hydrolysed and decarboxylated to 9-chloro-1(2)-methyltriazolo[4,5-f]quinolines (11c-d). Compound (1c) in refluxing acetonitrile with DMAD undergoes unusual cyclisation into triazolo-2-oxindole (5), then converted into 2-methyltriazolo[4,5-f]carbostyril-9-carboxylate (17).

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Paper | Regular issue | Vol 36, No. 2, 1993, pp. 281 - 286
Published online:
DOI: 10.3987/COM-92-6144
Reactivity of Ethanediyl S,S-Acetals -- 5. On the Aromatization of the Ring A in 3-Oxosteroid Derivatives

Romualdo Caputo, Carla Ferreri, Giovanni Palumbo,* Silvana Pedatella, and Francesco Russo

*Dipartimento di Chimica Organica e Biologica, Università di Napoli "Federico II", Via Mezzocannone 16, I-80134 Napoli, Italy


Ethanediyl S,S-acetal (1,3-dithiolane) derivatives of 3-oxosteroids, when treated with bromine in anhydrous chloroform at room temperature, undergo ring A aromatization following a dienone-benzene like steroidal skeleton rearrangement that leads to 1,4-dithian fused 4-methylestranes. The easy replacement of the sulphur atoms may afford 4-methylestranes with variously substituted A rings.

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Paper | Regular issue | Vol 36, No. 2, 1993, pp. 287 - 294
Published online:
DOI: 10.3987/COM-92-6151
A Convenient Route to 6-Aminocyclopenta[c]thiophen-4-one Derivatives

Patrick Dallemagne, Abdellah Alsaïdi, M. Boulouard, Sylvain Rault, and Max Robba*

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


Synthesis of 6-amino-5,6-dihydro-4H-cyclopenta[c]thiophen-4-one derivatives is achieved by cyclization of amino-2,5-dihalothienylpropinoic acids and subsequent dehalogenation.

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Paper | Regular issue | Vol 36, No. 2, 1993, pp. 307 - 314
Published online:
DOI: 10.3987/COM-92-6181
Insight into Novel Cyclization Reactions Using Acetic Anhydride in the Presence of 4-Dimethylaminopyridine

Johannes Aichner, Helmut Egg,* Dagmar Gapp, Sigrid Haller, Dietmar Rakowitz, and Ulrike Ramspacher

*Institut für Organische und Pharmazeutisch Chemie, Universität Innsbruck, Innrain 52, A-6020 Innsbruck, Austria


Reactions of acetic anhydride in the presence of 4-dimethylaminopyridine with 1,3-disubstituted ureas and hydrazobenzenes gave uracils and pyrazolinones respectively. Unsymmetrical 1,3-disubstituted ureas react regioselectively.

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Paper | Regular issue | Vol 36, No. 2, 1993, pp. 315 - 322
Published online:
DOI: 10.3987/COM-92-6188
Base-catalyzed Electrophilic Substitution in 2(1H)-Quinolinones

Rosario González, M. Teresa Ramos, Elena de la Cuesta, and Carmen Avendaño*

*Departamento de Química Orgánica y Farmacéutica, Facultad de Farmacia, Universidad Complutense de Madrid, Ciudad Universitaria, 28040 Madrid, Spain


Instead of tandem conjugate addition-α-alkylation to C3=C4 double bond of 2(1H)-quinolinones, regioselective C3-lithiation and subsequent C3-alkylation takes place by reaction with two equivalents of n-butyllithium and several electrophiles.

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Paper | Regular issue | Vol 36, No. 2, 1993, pp. 323 - 328
Published online:
DOI: 10.3987/COM-92-6197
Demethylation of Methoxypyridines with Sodium Trimethylsilanethiolate

Min-Jen Shiao,* Wei-Shen Ku, and Jih Ru Hwu

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


Demethylation of methoxypyridines was accomplished in 55-87% yield by use of ~1.5-2.5 equivalents of NaSSiMe3 in 1,3-dimethyl-2-imidazolidinone at 120-180 °C. This method was found applicable to a methoxyquinoline and methoxypyridines containing a second substituent, such as Cl, OMe, and COOMe.

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Paper | Regular issue | Vol 36, No. 2, 1993, pp. 329 - 343
Published online:
DOI: 10.3987/COM-92-6210
1H Nmr Spectra of Penylated Flavonoids and Pyranoflavonoids

Toshio Fukai and Taro Nomura*

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


1H Nmr examination of prenylated flavonoids has shown that the presence of the prenyl group at C-3, C-6, or C-8 position of flavone can be deduced from the chemical shift of methylene protons of prenyl group measured in acetone-d6. The chemical shifts of olefinic proton on pyran ring and A ring proton can be used to distinguish between linear type pyranoflavone and angular type pyranoflavone. The application of this 1H nmr method to the identification of Atalantia flavone and Artocarpus flavones is discussed.

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Paper | Regular issue | Vol 36, No. 2, 1993, pp. 345 - 358
Published online:
DOI: 10.3987/COM-92-6231
Furanoterpene Synthesis via Intramolecular Nitrile Oxide Cycloaddition Reaction: A Total Synthesis of (+)-Menthofuran

Kozo Shishido,* Koji Umimoto, Takeshi Takata, Osamu Irie, and Masayuki Shibuya

*Institute for Medicinal Resources, University of Tokushima, Sho-machi, Tokushima 770-8505, Japan


A fused furan assembling strategy based on an intramolecular [3+2] dipolar cycloaddition reaction of nitrile oxide has been applied to a total synthesis of perfumy furanomonoterpene (+)-menthofuran (1). The key cycloaddition substrates (9) and (12) are easily prepared via straightforward routes starting from (+)-citronellal and these are treated with sodium hypochlorite and p-chlorophenyl isocyanate, respectively. The cycloaddition reactions generate 10 : 1 mixture of diastereoisomeric isoxazolines (2a) and (2b) in good to excellent yields. The isoxazolines (2a,b) thus obtained are converted to (+)-menthofuran (1) by sequential reductive hydrolysis and alkaline hydrolysis (or vice versa) followed by acid treatment of the resulting β,γ-dihydroxy ketone (14).

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Review | Regular issue | Vol 36, No. 2, 1993, pp. 359 - 388
Published online:
DOI: 10.3987/REV-92-453
The Detoxin Complex. — A Naturally Occurring Safener

Wen-Ren Li, So-Yeop Han, and Madeleine M. Joullié*

*Department of Chemistry, University of Pennsylvania, 231 South 34th Street Philadelphia, PA 19104-6323, U.S.A.


The detoxin complex is a group of depsipeptide metabolites produced by the organism Streptomyces caespitosus var. detoxicus 7072GC1 as well as other strains of streptomyces. The complex is the first isolated natural product which displays a unique detoxification effect in plant and animal cells as its biological actvity. The structural investigations carried out to elucidate the structures of the congeners and the stereochemistry of the stereogenic centers are described. Structure-activity relationships are discussed. The different synthetic approaches to the parent amino acid, (-)-detoxinine, are compared. The syntheses of detoxins (-)-B1, (-)-B3, (-)-D1, and (+)-valyldetoxinine are described.

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16 data found. 1 - 16 listed