Regular Issue

Vol. 32, No. 7, 1991

18 data found. 1 - 18 listed
Communication | Regular issue | Vol 32, No. 7, 1991, pp. 1267 - 1272
Published online:
DOI: 10.3987/COM-91-5725
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


Glycosyl carbonates are shown to be excellent substrates to effect palladium catalyzed stereoselective C-glycosidations in good yields under mild conditions.

PDF (121KB)
Communication | Regular issue | Vol 32, No. 7, 1991, pp. 1273 - 1277
Published online:
DOI: 10.3987/COM-91-5734
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.


A synthesis of allylsilanes from lactones and protected hydroxy esters is reported. These allylsilanes were converted into novel oxygen heterocyclic compounds.

PDF (107KB)
Communication | Regular issue | Vol 32, No. 7, 1991, pp. 1279 - 1282
Published online:
DOI: 10.3987/COM-91-5765
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


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.

PDF (99KB)
Communication | Regular issue | Vol 32, No. 7, 1991, pp. 1283 - 1286
Published online:
DOI: 10.3987/COM-91-5766
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


Reductive photocyclization of α-methylthio- and α-arylthionamides (2a-c) gave six-membered lactams (3a-d) and five-membered lactams (4a,b).

PDF (92KB)
Paper | Regular issue | Vol 32, No. 7, 1991, pp. 1287 - 1296
Published online:
DOI: 10.3987/COM-91-5703
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


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.

PDF (204KB)
Paper | Regular issue | Vol 32, No. 7, 1991, pp. 1297 - 1300
Published online:
DOI: 10.3987/COM-91-5705
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


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.

PDF (82KB)
Paper | Regular issue | Vol 32, No. 7, 1991, pp. 1301 - 1305
Published online:
DOI: 10.3987/COM-91-5723
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


Curtius rearrangement of 3-trifluoroacetylamino-3-arylpropionyl azides gave 4-arylimidazolidin-2-ones via an anchimeric assistance reaction.

PDF (113KB)
Paper | Regular issue | Vol 32, No. 7, 1991, pp. 1307 - 1315
Published online:
DOI: 10.3987/COM-91-5735
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.


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).

PDF (280KB)
Paper | Regular issue | Vol 32, No. 7, 1991, pp. 1317 - 1325
Published online:
DOI: 10.3987/COM-91-5736
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


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).

PDF (251KB)
Paper | Regular issue | Vol 32, No. 7, 1991, pp. 1327 - 1340
Published online:
DOI: 10.3987/COM-91-5743
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.


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.

PDF (321KB)
Paper | Regular issue | Vol 32, No. 7, 1991, pp. 1341 - 1350
Published online:
DOI: 10.3987/COM-91-5748
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


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.

PDF (242KB)
Paper | Regular issue | Vol 32, No. 7, 1991, pp. 1351 - 1356
Published online:
DOI: 10.3987/COM-91-5750
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


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).

PDF (163KB)
Paper | Regular issue | Vol 32, No. 7, 1991, pp. 1357 - 1364
Published online:
DOI: 10.3987/COM-91-5754
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


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.

PDF (198KB)
Paper | Regular issue | Vol 32, No. 7, 1991, pp. 1365 - 1370
Published online:
DOI: 10.3987/COM-91-5758
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.


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.

PDF (192KB)
Paper | Regular issue | Vol 32, No. 7, 1991, pp. 1371 - 1376
Published online:
DOI: 10.3987/COM-91-5759
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


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.

PDF (153KB)
Paper | Regular issue | Vol 32, No. 7, 1991, pp. 1377 - 1386
Published online:
DOI: 10.3987/COM-91-5761
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


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.

PDF (225KB)
Paper | Regular issue | Vol 32, No. 7, 1991, pp. 1387 - 1390
Published online:
DOI: 10.3987/COM-91-5772
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


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.

PDF (104KB)
Review | Regular issue | Vol 32, No. 7, 1991, pp. 1391 - 1429
Published online:
DOI: 10.3987/REV-91-429
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.


The structures, biological activities, and syntheses of marine natural products containing indole and dihydroindole nuclei are reviewed.

PDF (862KB)
18 data found. 1 - 18 listed