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. 7, 1991
Published online:
■ Palladium Catalyzed Reactions of Unsaturated Carbohydrates — A Route to C-Glycosides
Gerhardus J. Engelbrecht and Cedric W. Holzapfel*
*Department o f Chemistry and Biochemistry, Rand Afrikaans University, P.O. Box 524, Auckland Park, 2006, Johannesburg, South Africa
Abstract
Glycosyl carbonates are shown to be excellent substrates to effect palladium catalyzed stereoselective C-glycosidations in good yields under mild conditions.
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■ The Synthesis of Chiral Allylsilanes, Spiroketals and Dioxaspiro-Compounds
Vernon G. S. Box* and David P. Brown
*Department of Chemistry, City College of The City University of New York, New York, NY 10031,U.S.A.
Abstract
A synthesis of allylsilanes from lactones and protected hydroxy esters is reported. These allylsilanes were converted into novel oxygen heterocyclic compounds.
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■ Synthetic Studies on Podophyllum Lignans: Tributyltin Hydride-induced Radical Cyclization and Intramolecular Heck Reaction of α-Benzylidene-β-(o-bromobenzyl)-γ-lactones
Hiroyuki Ishibashi,* Katsuhiro Ito, Masayo Tabuchi, and Masazumi Ikeda*
*Kyoto Pharmaceutical University, Misasagi-Shichonocho, Yamashina, Kyoto 607-8414, Japan
Abstract
Tributyltin hydride-induced radical cyclization of the (Z)-α-benzylidene-β-(o-bromobenzyl)-γ-lactone (16) gave the 6-endo cyclization product, (±)-deoxyisopicropodophyllin (18), and the 5-exo cyclization product (19). On the other hand, the intramolecular Heck reaction of 16 provided (±)-γ-apopicropodophyllin (20) as a sole cyclization product.
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■ Reductive Photocyclization of α-Methylthio- and α-Arylthioenamides
Takeaki Naito,* Hiromi Tanada, Toshiko Kiguchi, and Ichiya Ninomiya
*Kobe Women’s College of Pharmacy, Motoyamakita, Higashinada, Kobe 658-8558, Japan
Abstract
Reductive photocyclization of α-methylthio- and α-arylthionamides (2a-c) gave six-membered lactams (3a-d) and five-membered lactams (4a,b).
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■ Three New Diels-Alder Type Adducts from the Roots of Sorocea bonplandii Baillon
Irene Massana,* Franco Ferrari, Franco Delle Monache, Rosendo A. Yunes, Joao B. Calixto, and Terezinha Bisognin
*Centro Chimica dei Recettori, C.N.R. , Università Cattolica del Sacro Cuore, Largo Francesco Vito 1, 00168 Roma, Italy
Abstract
Three new ketalized Diels-Alder type adducts named soroceal (1), sorocein A (2), sorocein B (3), were isolated from the methanolic extract of the roots of Sorocea bonplandii. The structures were assigned on the basis of chemical and spectroscopic evidences.
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■ Studies on Aconitum Species. XIV. Deoxygenation of Pseudokobusine to Kobusine
Koji Wada,* Hideo Bando, and Norio Kawahara
*Hokkaido Institute of Pharmaceutical Sciences, 7-1 Katsuraoka-cho, Otaru 047-02, Japan
Abstract
Pseudokobusine (1) was deoxygenated through conversion into the imidazoylthiocarbonyl derivative with N,N’-thiocarbonyldiimidazole and then treated with tri-n-butylstannane. This reaction sequence produced kobusine (2) in a good yield.
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■ A New and Efficient Synthesis of 4-Arylimidazolidin-2-ones
Sylvain Rault, Olivier N. Tembo, Patrick Dallemagne, and Max Robba*
*Laboratoire de Chimie Thérapeutique, U. F. R. des Sciences Pharmaceutiques, Université de Caen, 1, rue Vaubénard, 14032 Caen Cedex, France
Abstract
Curtius rearrangement of 3-trifluoroacetylamino-3-arylpropionyl azides gave 4-arylimidazolidin-2-ones via an anchimeric assistance reaction.
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■ New Synthetic Derivatives of Aconitine, Delphonine and N-Deacetyllappaconitine
Samir A. Ross and S. William Pelletier*
*Institute for Natural Products Research, School of Chemical Sciences, The University of Georgia, Chemistry Building, Athens, Georgia 30602-2556, U.S.A.
Abstract
This paper reports the synthesis and spectral data for 3,13-diacetylaconitine (3), 3,13,15-triacetylaconitine (4), 3,13-diacetyl-14-benzoylaconine (7), aconine pentaacetate (10), delphonine methiodide (11), 8,9-diacetyllappaconitine (12), N-deacetyl-N-methyllappaconitine (13), N-deacetyl-N-N-dimethyllappaconitine (14), N-deacetyl-N-benzoyllappaconitine (15), N-deacetyl-N-o-anisoyllappaconitine (16), N-deacetyl-N-p-anisoyllappaconitine (17), N-deacetyl-N-(3,4,5-trimethoxybenzoyl)lappaconitine (18), N-deacetyl-N-p-nitrobenzoyllappaconitine (19), N-deacetyl-N-triphenylmethyllappaconitine (20), and N-deacetyl-N-(3,3-dimethylacryloyl)lappaconitine (21).
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■ Triethylamine, Ethanol — Mediated Disciplined Reactions of S-Benzylisothiouronium Chloride with Unsaturated 2-Oxazolin-5-ones: Synthesis of (Z)-2-Amino-4-arylmethylene-2-imidazolin-5-ones, 5-Benzoylamino-2-benzylthio-6-oxo-4,4-spirocyclohexyl-1,4,5,6-tetrahydropyrimidine, and Their Structure
Arya K. Mukerjee,* Kiran Joseph, Seyed-Saied Homami, and Ahmad M. Tikdari
*Department of Chemistry, Faculty of Science, Banaras Hindu University, Varanasi - 221005, India
Abstract
Triethylamine-mediated condensation of S-benzylisothiouronium chloride with (Z)-4-arylmethylene-2-phenyl-2-oxazolin-5-ones (4) in ethanol gives (Z)-2-amino-4-arylmethylene-2-imidazolin-5-ones (7), whereas the similar reaction with 4-cyclohexylidene-2-phenyl-2-oxazolin-5-ones (5) produces 5-benzoylamino-2-benzylthio-6-oxo-4,4-spirocyclohexyl-1,4,5,6-tetrahydropyrimidine (15) which on aminolyses with arylamines affords the corresponding 2-arylamino derivatives (16).
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■ An Intramolecular 1,3-Dipolar Cycloaddition Approach to 5,6,7,8-Tetrahydro-4-ethoxy-6-hydroxymethyl-2-pivaloylamino-5-deazapteridin-5(8H)-one, a Potentially Useful Intermediate to 5-Deaza- and 5,10-Dideaza-5,6,7,8-tetrahydrofolic Acid Analogs
Edward C. Taylor* and Partha S. Ray
*Department of Chemistry, Princeton University , Princeton, New Jersey 08544, U.S.A.
Abstract
2-Amino-4,6-dichloro-5-formylpyrimidine was converted to the title compound (12), a potentially useful intermediate for the synthesis of 5-deaza- and 5,10-dideaza-5,6,7,8-tetrahydrofolic acid analogs. The key steps in the sequence were an intramolecular 1,3-dipolar cycloaddition of an in situ generated nitrile oxide (10b) to give the isoxazolo[3’,4’:4,5]pyrido[2,3-d]pyrimidine (11b) followed by reductive cleavage of the isoxazoline N-O bond.
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■ Synthetic Studies on Indole Alkaloids. IV. Studies on N-Phenylsulfonyl-2-methylindoles on Intramolecular Cyclizations
Mario Rubiralta,* Anna Diez, Cristina Vila, Yves Troin, and David Miguel
*Laboratory of Organic Chemistry, Faculty of Pharmacy, University of Barcelona, Av. de Joan XXIII, s/n, 08028 Barcelona, Spain
Abstract
The synthesis of 1-(2-hydroxyethyl)-2-[2-methyl-N-(phenylsulfonyl)-2-indolyl]-4-piperidone ethylene ketal (4) by two alternative ways and the study of its intramolecular cyclization using potassium tert-butoxide are reported.
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■ A Convenient Synthesis of Adenosine 3’,5’-Cyclic Phosphate (cAMP) Benzyl and Methyl Triesters
Shigehiro Kataoka,* Riichiro Uchida, and Nobuyuki Yamaji
*Research and Development Division, Kikkoman Corporation, 399 Noda, Noda-shi, Chiba 278, Japan
Abstract
The benzyl and methyl triesters of cAMP were synthesized from cAMP tri-n-butylammonium salt by alkylation with alkyl halides in the presence of Na2CO3 in dimethylacetamide (DMA).
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■ Components of the Root Bark of Morus insignis Bur. 2. Structures of Four New Isoprenylated Xanthones, Morusignins E, F, G. and H
Yoshio Hano, Tsuyoshi Okamoto, and Taro Nomura*
*Faculty of Pharmaceutical Sciences, Toho University, 2-2-1, Miyama, Funabashi, Chiba 274-8510, Japan
Abstract
Four new isoprenylated xanthones, morusignins E (1), F (2), G (3), and H (4) were isolated from the root bark of Morus insignis Bur. (Moraceae), collected in Paraguay. The structures of morusignins E - H were shown to be 1 - 4, respectively, on the basis of spectroscopic data.
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■ Isolation of Dihydroavicine and Rhetsinine from Zanthoxylum budrunga. The Revision of 1H and 13C Nmr Spectral Assignments for Sanguinarine
Balawant S. Joshi,* Mohindar S. Puar, Kristi M. Moore, and S. William Pelletier
*Scool of Chemical Sciences, Institute for Natural Products Research, The University of Georgia, Chemistry Building, Athens, Georgia 30602-2556, U.S.A.
Abstract
Dihydroavicine (1) and rhetsinine (hydroxyevodiamine) (5) have been isolated from the bark of Zanthoxylum budrunga Wall. The 1H and 13C nmr assignments reported earlier for sanguinarine have been revised on the basis of HECTOR and selective INEPT studies.
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■ Acid Catalyzed Photoreaction of 5-Chloro-1,3-dimethyluracil with Substituted Benzenes
Kazue Ohkura, Kohki Matsuda, and Koh-ichi Seki*
*Faculty of Pharmaceutical Sciences, Higashi-Nippon-Gukuen University, Ishikari-Tobetsu, Hokkaido 061-0293, Japan
Abstract
The photo-induced substitution of 5-chloro-1,3-dimethyluracil with substituted benzenes, affording the corresponding 5-aryl-1,3-dimethyluracils in appreciable yields, was significantly promoted by the addition of trifluoroacetic acid to the reaction mixture.
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■ A New Synthesis of N-Tosylindole from Aniline via ortho-Substituted N-Tosylanilides
Yasushi Murai, Gen Masuda, Seiichi Inoue,* and Kikumasa Sato
*Department of Applied Chemistry and Biotechnology, Faculty of Engineering, Yokohama National University, Tokiwadai 156, Hodogaya-ku, Yokohama 240-8501, Japan
Abstract
A simple and very efficient synthesis of N-tosylindole is described, based on the acid-catalyzed cyclization of ortho-alkylated N-tosylanilides, which can be prepared from aniline and dialkyl sulfide by [2,3]sigmatropic rearrangements.
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■ Synthesis of 4-(Tributylstannyl)pyridazines by Inverse Electron-demand Diels-Alder Reaction of 1,2,4,5-Tetrazines with Tributylstannylacetylenes
Takao Sakamoto, Nobuyuki Funami, Yoshinori Kondo, and Hiroshi Yamanaka*
*Pharmaceutical Institute, Tohoku University, Aobayama, Sendai 980-8578, Japan
Abstract
Inverse electron-demand Diels-Alder reaction of 3,6-disubstituted 1,2,4,5-tetrazines with tributylstannylacetylenes containing a substituent gave 4-(tributylstannyl)pyridazines. Particularly, dimethyl 1,2,4,5-tetrazine-3,6-dicarboxylate gave 4-(tributylstannyl)pyridazines in good yields. Substitution reaction of 3,6-diphenyl-4-(tributylstannyl)pyridazine was also described.
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■ Marine, Nitrogen-containing Heterocyclic Natural Products — Structures and Syntheses of Compounds Containing Indole 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 indole and dihydroindole nuclei are reviewed.