HETEROCYCLES
An International Journal for Reviews and Communications in Heterocyclic ChemistryWeb Edition ISSN: 1881-0942
Published online by The Japan Institute of Heterocyclic Chemistry
Regular Issue
Vol. 32, No. 4, 1991
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■ Photoinduced Fragmentation of Pyrido[2,1-f]-as-triazinium-4-olate and Its Benzologue. A Contribution to the Mechanism of Curtius Rearrangement
Sándor Bátori, András Messmer,* and Hans-Joachim Timpe
*Central Research Institute for Chemistry, Hungarian Academy of Sciences, H-1025 Budapest, Pusztaszeri ut 59-67, P.O.Box 17, Hungary
Abstract
The zwitterionic pyrido[2,1-f]-as-triazinium-4-olates (1a-b) and as-triazino[6,1-a]isoquinolinium-1-olate (10) were photolysed to give acid amides (5) and (11), respectively. Formation of 5 through acylnitrene (4) was supported in separate experiment.
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■ A New Entry to [2.3.4]Cyclazines
Yasuyoshi Miki,* Hiroko Hachiken, Masami Yoshikawa, Shoji Takemura, and Masazumi Ikeda
*Faculty of Pharmaceutical Sciences, Kinki University, 3-4-1, Kowakae, Higashi-Osaka 577-8502, Japan
Abstract
Treatment of 2,3-dihydro-2-methyl-3-phenyl-1H-pyrazino[3,4,5-cd]indolizine 2-oxides (5) with trifluoroacetic anhydride gave new heterocyclic six-membered betaines (6) which underwnet 1,3-dipolar cycloaddition reaction with dimethyl acetylenedicarboxylate and maleimides in hot toluene to yield the corresponding cycloadducts (7) and (8). Treatment of the maleimide adducts (8) with p-toluenesulfonic acid in boiling acetic acid gave the [2.3.4]cyclazines (9).
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■ Novel Synthesis of Thiaznonanam Using Sulfur Dichloride as a Sulfur Transfer Reagent
Mitsuo Komatsu,* Masaaki Mohri, Shoichiro Kume, and Yoshiki Ohshiro*
*Department of Applied Chemistry, Faculty of Engineering, Osaka University, 2-1 Yamadaoka, Toyonaka, Osaka 560-0043, Japan
Abstract
Hitherto unknown or rarely reported sulfur-containing bicyclic β-lactams, 6- and 7-thianonanams, were synthesized by addition of sulfur dichloride to N-allyl-β-styryl-β-lactam.
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■ Synthetic Applications of 2-(1,3-Dithian-2-yl)indoles. III. A New Route to Tetracyclic [ABCD] Intermediates in the Synthesis of Aspidosperma Indole Alkaloids
Yves Troin, Anna Diez, Jean-Luc Bettiol, Mario Rubiralta,* David S. Grierson, and Henri-Phillippe Husson
*Laboratory of Organic Chemistry, Faculty of Pharmacy, University of Barcelona, Av. de Joan XXIII, s/n, 08028 Barcelona, Spain
Abstract
The synthesis of tetracyclic [ABCD] framework of Aspidosperma alkaloids has been achieved via allylamine-enamine isomerization using (Ph3P)3RhCl in hot aqueous acetonitrile of the 1,2,5,6-tetrahydro-3-(indolylethyl)pyridine (13) which in turn was obtained by Raney nickel desulfurization of the corresponding 2-(1,3-dithia-2-yl)indole (5a).
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■ On the Reaction of 2,2,6,6-Tetramethyl-3,5-heptanedione ("Dipivaloylmethane") with Oxalyl Chloride
Gert Kollenz,* C. Oliver Kappe, and Hesham Abd el Nabey
*Institute of Organic Chemistry, University of Graz, Heinrichstr. 28, A-8010 Graz, Austria
Abstract
Refluxing of dipivaloylmethane (1) in an excess of oxalyl chloride gives a mixture containing the 5-chloro-furanone derivatives (2), (3), and (4), which then can be completely converted into the 5-tert-butyl-4-pivaloylfuran-2,3-dione (5). Compounds (2-5) are hydrolyzed to the carboxylic acid (6), which in reverse is easily recyclized to 5.
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■ A Convenient Preparation of Sterically Crowded 1,9-Disubstituted Dibenzothiophenes and 3,3’-Disubstituted Diaryl Sulfides
Naomichi Furukawa,* Takeshi Kimura, Yoji Horie, and Satoshi Ogawa
*Department of Chemistry, University of Tsukuba, 1-1-1 Ten-nodai, Tsukuba-shi, Ibaraki, 305-8571, Japan
Abstract
Thianthrene-5-oxide (1) reacted with 2.2 equivalents of lithium diisopropylamide to give 4,6-dilithiated 1 wich was converted to 4,6-disubstituted thianthrene-5-oxides (3). 3 afforded sterically crowded 1,9-disubstituted dibenzothiophenes (4) in moderate yields on treatment with n-butyllithium or phenyllithium.
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■ Role of Heterocycles on the Stereoselective Reactions of α-Sulfinyl Carbanions Using Optically Active 2-Pyridylmethyl p-Tolyl and 2-(N-Methylimidazolyl)methyl p-Toyl Sulfoxides with Aldehydes
Naomichi Furukawa,* Takahiro Sagae, and Satoshi Ogawa
*Department of Chemistry, University of Tsukuba, 1-1-1 Ten-nodai, Tsukuba-shi, Ibaraki, 305-8571, Japan
Abstract
Optically active 2-pyridylmethyl p-tolyl (1) and 2-(N-methylimidazolyl)methyl p-tolyl sulfoxides (2) were synthesized and the reactions of their chiral α-sulfinyl carbanions with aldehydes afforded stereoselectively the condensation products. The absolute configurations of the products were determined by X-ray crystallographic analysis and chemical reactions. The mechanism for the reactions is described.
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■ Regio- and Chemoselective Alkylation of 2,3-Dialkylindoles. A Convenient Preparation of 2,3,3-Trialkyl-3H-indoles
Colin W. G. Fishwick,* Andrew D. Jones, and Michael B. Mitchell
*School of Chemistry, The University of Leeds, Leeds, LS2 9JT, U.K.
Abstract
Various 3-alkyl-2,3-dimethyl-3H-indoles were prepared by addition of an alkyl iodide to a solution of the lithium salt of 2,3-dimethylindole. In contrast, reaction with ethyl chloroformate or trimethylsilyl chloride afforded the N-substituted indoles exclusively. The reaction failed with cyclohexylcarboxaldehyde.
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■ Synthesis of Two New Thiazole-containing Oligopeptides as Potential DNA Minor Groove Binding Analogs of Netropsin
Bertrand Plouvier, Christian Bailly, Raymond Houssin, and Jean-Pierre Hénichart*
*Institut de Chimie Pharmaceutiqe, Université de Lille 2, 3, rue du Professeur Laguesse, BP 83, 59006 Lille Cedex, France
Abstract
On the basis of previous studies on synthetic models related to the antibiotic agents Netropsin and Distamycin-A, the design and synthesis of two potential DNA minor groove ligands are described. Methia-Nt and Isothia-Nt were prepared by liquid-phase peptidic synthesis from the key compounds ethyl 2-amino-5-methylthiazole-4-carboxylate (1) and ethyl 2-aminothiazole-5-carboxylate (8) respectively.
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■ Cyclotriphosphazene Linked Tetraphenylporphyrins
Iykkiam Immanuel Selvaraj, Damodar Reddy, Vadapalli Chandrashekar,* and Tavarekere Kalliah Chandrashekar*
*Department of Chemistry, Indian Institute of Technology, Kanpur 208016, India
Abstract
Condensation of the functionalised cyclophosphazene aldehyde, N3P3(OC6H5)5(m-OC6H4-CHO) (3) with pyrrole affords the tetraphenylporphyrin (4) containing the cyclophosphazene unit. This has been characterised by spectroscopic and analytical methods. Kinetics of metallation (Cu2+, Zn2+) of (4) indicate slower rates of insertion relative to normal tetraphenylporphyrins. The esr spectrum indicates an axial symmetry for the Cu2+ derivative (6).
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■ Preparation of Crown Ethers with Isoxazolyl-Lariats: Homologation of Isoxazole Aldehydes, and a Critical Comparison of Lariat Functional Moieties for Lanthanide Extraction
Xiong Bing Xia, Mark S. Munsey, Hongshan Du, Chien M. Wai, and Nicholas R. Natale*
*Department of Chemistry, University of Idaho, 301 Renfrew Hall, Moscow, ID 83844-2343, U.S.A.
Abstract
A critical comparison of several lariat ether functional moieties is presented. The synthesis of two isoxazolyl-lariat ethers is described. The lariat ether (2, n=1) undergoes β-fragmentation on electron transfer reductive ring-opening with samarium diiodide. The isoxazole moiety was then homologated to overcome this problem, and isoxazole lariat ether (2, n=3) was obtained. The isoxazole (2, n=3) and β-diketone (3, n=3) crowns were evaluated in lanthanide shift studies and liquid-liquid extraction studies. Finally, lateral metalation and electrophilic quenching with carbon dioxide produced the carboxylic acid (12) which proved to be an efficient ligand for the liquid-liquid extraction of lanthanides.
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■ Reissert Compound Studies LXIII: Preparation of Reissert Compounds Using Diethylaluminum Cyanide
Frederick F. Duarte and Frank D. Popp*
*Department of Chemistry, University of Missouri-Kansas City, Missouri 64110, U.S.A.
Abstract
Reissert compounds and analogs were synthesized from the reaction of an acid halide, heterocyclic base and diethylaluminum cyanide. This new method of Reissert compound synthesis gave yields comparable to other synthetic routes.
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■ Synthesis of N-Alkyl-N’-(4-diazo-5-pyrazolyl)ureas and Their Conversion into Pyrazolo[3,4-d][1,2,3]triazole and Pyrazolo[3,4-d]oxazole Derivatives
Chiara B. Vicentini, Augusto C. Veronese, Tiziana Poli, Mario Guarneri, and Paolo Giori*
*Dipartimento di Scienze Farmaceutiche, Università di Ferrara, via Fossato di Mortara 17, I-44100, Ferrara, Italy
Abstract
The synthetic route to N-alkyl-N’-(4-diazo-5-pyrazolyl)ureas (4) starting from pyrazolo[4,3-c][1,2,5]oxadiazin-3(5H)-one (1) is described. Compounds (4) undergo thermal and photochemical reactions affording pyrazolo[3,4-d][1,2,3]triazoles (5) and pyrazolo[3,4-d]oxazoles (7) respectively.
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■ Efficient Alkylation and Acylation of Pyrazine 1-Oxides
Yutaka Aoyagi, Atsushi Maeda, Masami Inoue, Mitsuhiro Shiraishi, Yuki Sakakibara, Yuko Fukui, and Akihiro Ohta,* Kenzo Kajii, and Yoshio Kodama
*Tokyo College of Pharmacy and Life Science, 1432-1 Horinouchi, Hachioji, Tokyo 192-0392, Japan
Abstract
Reactions of pyrazine 1-oxides with electrophiles in the presence of LTMP (lithium 2,2,6,6-tetramethylpiperidine) and TMEDA (N,N,N ’,N ’-tetramethylethylenediamine) afforded 2-alkyl- and 2-acylpyrazine 1-oxides in good yields, and the products could be deoxygenated with PBr3 and Raney Ni successfully.
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■ Reaction of Alkyl Radicals with γ-Pyron Derivatives, 2-Methoxycarbonylchromone and Dimethyl Chelidonate.
Masaru Tada* and Naruo Mori
*Department of Chemistry, School of Science and Engineering, Waseda University, 3-4-1 Okubo, Shinjuku-ku, Tokyo 169-8555, Japan
Abstract
The reaction of alkyl radicals with 2-methoxycarbonylchromone (3) and dimethylchelidonate (4) gave dimeric products, 2,2’-bis -(2,2’-dimethoxycarbonyl-3,3’-dialkyl)chromanone (5 and 6) and 2,2’-(bis-2,2’,6,6’-tetramethoxycarbonyl-3,3’-dialkyl)-2,3-dihydro-4-oxo-4H-γ-pyran (8 and 9). Both the dimeric products consist of two stereoisomers, meso and dl at the central bond of the dimer. The formation of the dimeric products is accounted for by the initial attack of alkyl radical to the α-position of the γ-pyrone derivatives having ester group at β-position. The intervention of the capto-dative radicals is supported by the thermal equilibrium with the dimeric products.
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■ Marine, Nitrogen-containing Heterocyclic Natural Products. Structures and Syntheses of Compounds Containing Quinoline and/or Isoqiunoline Units
Mercedes Alvarez, Marisa Salas, and John A. Joule*
*Department of Chemistry, University of Manchester, Oxford Road, Manchester, M13 9PL, U.K.
Abstract
The structures, biological activities, and syntheses of marine, natural products containing quinoline and/or isoquinoline nuclei are reviewed.
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■ The Role of Lone Pair Interactions in the Chemistry of the Monosaccharides. Stereo-electronic Effects in Unsaturated Monosaccharides
Vernon G. S. Box*
*Department of Chemistry, City College of The City University of New York, New York, NY 10031 U.S.A.
Abstract
The X-ray crystallographic structural data for simple unsaturated monosaccharides do not support the participation of the electron density of a C2-C3 π bond in the modification of the geometry at the anomeric center, or the existence of a vinylogous anomeric effect in glycals. The delocalization phenomena (n-σ*, n-π* and π-σ*) are insignificant in the ground states of the simple sugars, and n-n repulsions are the dominant stereo-electronic effects in these molecules.