Regular Issue

Vol. 51, No. 6, 1999

23 data found. 1 - 23 listed
Communication | Regular issue | Vol 51, No. 6, 1999, pp.1225-1228
Published online:
DOI: 10.3987/COM-99-8498
[4+3] Cycloadditions with c-Heteroannulated Furans — Synthesis of Novel Annulated Tropones

Stephan Reck, Christian Näther, and Willy Friedrichsen*

*Institute of Organic Chemistry, Ott-Hahn-Platz 4, D-24098 Kiel, Germany

Abstract

Furo[3,4-d]oxazole (1a) and furo[3,4-d]thiazole (1b) react with 1,3-dimethyloxyallyl cationic species to give the [4+3] cycloaddition products (3a,b). The ring opening reaction of these adducts with H2SO4/Et2O yields the annulated hydroxytropones (4a,b or 5a,b).

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Communication | Regular issue | Vol 51, No. 6, 1999, pp.1229-1232
Published online:
DOI: 10.3987/COM-99-8521
Crystal Structures of N,N'-Bis-(1-naphthylmethyl)-1,4,10,13-tetraoxa-7,16-diazacyclooctadecane Complexed with Potassium and Barium Thiocyanates

Kanji Kubo,* Tadamitsu Sakurai, Nobuo Kato, and Akira Mori

*Instituete of Advanced Material Study, 86, Kyushu University, 6-1, Kasuga-koen, Kasuga 816-8580, Japan

Abstract

The crystal structures of N, N’-bis(1-naphthylmethyl)-4,13-diaza-18-crown-6 (1)-KNCS and 1-Ba(NCS)2-H2O complexes were analyzed by X-Ray crystallography. The structure of the 1-Ba(NCS)2-H2O complex differs significantly from that of the 1-KNCS complex. The K+ cation is sevenfold, Ba2+ cation ninefold coordinated. The two naphthalene rings adopt an anti conformation for 1-KNCS and syn conformation for 1-Ba(NCS)2-H2O with the crown ether ring.

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Communication | Regular issue | Vol 51, No. 6, 1999, pp.1233-1235
Published online:
DOI: 10.3987/COM-99-8531
Short Step Syntheses of a Natural Product, 6-Cyano-5-methoxy-12-methylindolo[2,3-a]carbazole and Novel 6-Aminoindolo[2,3-a]thiazolo[5,4-c]carbazoles

Hiroyuki Hayashi, Yoshiaki Suzuki, and Masanori Somei*

*Faculty of Pharmaceutical Scicences, Kanazawa University, 13-1 Takara-machi, Kanazawa 920-0934, Japan

Abstract

Starting from indigo, simple synthetic methods for 6-cyano-5-methoxy-12-methylindolo[2,3-a]carbazole and novel 6-aminoindolo[2,3-a]thiazolo[5,4-c]carbazoles are achieved using only conventional reagents.

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Communication | Regular issue | Vol 51, No. 6, 1999, pp.1237-1242
Published online:
DOI: 10.3987/COM-99-8542
Preparations of Melatonin and 1-Hydroxymelatonin, and Its Novel Nucleophilic Dimerization to (±)-3a,3a'-Bispyrrolo[2,3-b]indoles

Masanori Somei,* Naoki Oshikiri, Masakazu Hasegawa, and Fumio Yamada

*Faculty of Pharmaceutical Scicences, Kanazawa University, 13-1 Takara-machi, Kanazawa 920-0934, Japan

Abstract

A unique synthetic method for melatonin was established through biologically promising synthetic intermediates. 1-Hydroxymelatonin was prepared as crystals for the first time. It reacted with 85% formic acid to give (±)-3a,3a’-bispyrrolo[2,3-b]indole compound, whose structure was unequivocally determined by X-Ray crystallographic analysis.

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Paper | Regular issue | Vol 51, No. 6, 1999, pp.1243-1256
Published online:
DOI: 10.3987/COM-98-S(H)36
Universal Standard Reagents. The Use of 3-(2,4-Dinitroanilino)propanol (DNAP) and 1-(2,4-Dinitrophenyl)-4-hydroxypiperidine(DNPP) in Glycosylation and Selective Hydrolysis of Ester Glucosides

Abraham Patchornik,* Alfred Hassner,* Maria Kramer, Hugo E. Gottlieb, and Miriam Cojocaru

*Department of Chemistry, Bar-Ilan University, Ramat-Gan 529001, Israel

Abstract

We demonstrate the utility of the new principle of Universal Standard Reagents (USR) in glycosylation of protected sugars and selective hydrolysis of ester glycosides by means of 3-(2,4-dinitroanilinopropanol) (DNAP) and 1-(2,4-dinitrophenyl)-4-hydroxypiperidine (DNPP). Quantitative determination of each individual sugar derivative was carried out using extinction coefficients at λmax (~350 nm) on the micromole scale, eliminating the need for specific standards. The selective hydrolysis of β-DNAP-tetra-O-acetyl- and O- aroyl-glycosides was examined by different O- and N-bases using quantitative assess-ment by TLC and HPLC. DCI/NH3 MS of anomers and NMR-spectra of partially acylated glucosides are discussed.

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Paper | Regular issue | Vol 51, No. 6, 1999, pp.1257-1273
Published online:
DOI: 10.3987/COM-98-8412
Novel Rearrangement of Pyrrolo[2,1-c][1,4]benzodiazepines into Pyrrolo[2,1-b]quinazolinones, Analogous of Alkaloid, Vasicinone

Sandrine Jolivet-Fouchet, Frédéric Fabis, Philippe Bovy, Philippe Ochsenbein, and Sylvain Rault*

*Centre d' Etudes et de Recherche, sur le Médicament de Normandie (CERMN), 5, rue Vaubénard, 14032 Caen Cedex, France

Abstract

Tetrahydropyrrolo[2,1-c][1,4]benzodiazepin-5,11-diones (4) and (22-24) in concentrated hydrochloric acid rearranged after 30 mm into new oxohexahydropyrrolo [2,1-b][1,4]qunazolinecarboxyhc acids (5) and (25-27) in good yields. Quinazolinone (5) was then treated in various conditions to lead to the corresponding esters and carboxamides (28-34).

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Paper | Regular issue | Vol 51, No. 6, 1999, pp.1275-1282
Published online:
DOI: 10.3987/COM-98-8471
Probing the TCDD Receptor: Synthesis of 5,6-Dihydro-6a,11,11b-triazabenzo[a]fluorene·PF6, a Potential Ligand

Joakim Tholander and Jan Bergman*

*Department of Organic Chemistry, Biosciences at Novum, Karolinska Institutet, S-141 57 Huddinge, Sweden

Abstract

With the aim of investigating whether the ability of omeprazole (3) to activate the TCDD receptor is due to an internal cyclization process, 5,6-dihydro-6a,11,11b-triazabenzo[α]fluorene. PF6 (6) (X=PF6) has been designed and synthesized via a one-pot Mitsunobu reaction. An improved synthesis of the tosylate (10) of 2-(2-hydroxyethyl)pyridine has also been developed.

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Paper | Regular issue | Vol 51, No. 6, 1999, pp.1283-1294
Published online:
DOI: 10.3987/COM-99-8481
Alkylidenecarbene Insertion into a Nitrogen Lone Pair: An Unexpected Synthesis of Dihydropyrroles from Alkynyliodonium Salts

Ken S. Feldman,* Pamela A. Mingo, and Paul C. D. Hawkins

*Department of Chemistry, The Pennsylvania State University, University Park, Pennsylvania 16802, U.S.A.

Abstract

A novel intramolecular reaction between an alkylidenecarbene and the lone pair of electrons on a carbamate’s nitrogen is described. The reaction occurs preferentially over an available 1,5 C-H insertion and gives substituted dihydropyrroles upon workup.

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Paper | Regular issue | Vol 51, No. 6, 1999, pp.1295-1301
Published online:
DOI: 10.3987/COM-99-8484
Synthesis of Tetrazolo[1,5-a][1,4]benzodiazepin-6-ones via Intramolecular Azide Cycloadditions onto the Cyano Group

Gianluigi Broggini, Luisa Garanti,* Giorgio Molteni, and Gaetano Zecchi

*Dipartimento di Chimica Organica e Industriale, Centro C.N.R., Università degli Studi di Milano, via Golgi 19, I-20133 Milano, Italy

Abstract

Intramolecular azide cycloadditions onto the cyano group are described as a synthetic tool for a number oftetrazolo[1,5-a][1,4]benzodiazepin-6-ones (3).

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Paper | Regular issue | Vol 51, No. 6, 1999, pp.1303-1309
Published online:
DOI: 10.3987/COM-99-8487
Synthesis and Structural Features of 11H-Tetrazolo[1,5-c][2,3]benzodiazepines

Alba Chimirri,* Maria Zappalà, Rosaria Gitto, Silvana Quartarone, and Francesca Bevacqua

*Dipartimento Farmaco-Chimico, Università di Messina, Viale Annunziata, 98168 Messina, Italy

Abstract

A synthetic approach to new 11H-tetrazolo[1,5-c][2,3]benzodiazepine derivatives starting from 3,5-dihydro-4H-2,3-benzodiazepin-4-ones is described. The structural features of compounds obtained were ascertained by NMR spectroscopy. The proton and carbon assignments were made with the aid of two-dimensional heteronuclear chemical shift-correlation experiments.

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Paper | Regular issue | Vol 51, No. 6, 1999, pp.1311-1319
Published online:
DOI: 10.3987/COM-99-8488
Synthesis of Some New Pyranoquinoline and Related Heterocyclic Systems

Marzoog S. Al-Thebeiti

*Department of Chemistry, Faculty of Applied Sciences, Umm Al-Qura University, Makkah Almukkarramah, P. O. Box 6876, Saudi Arabia

Abstract

The reaction of cinnamonitriles (2a,b) with 5-dimethylaminosulfonyl-8-quinolinol (1) gave the corresponding pyranoquinoline derivatives (3a,b). The latter derivatives are used in the synthesis of pyrido[2’,3’:6,5]pyrano[3,2-h]quinolines and pyrimido[4’,5’:6,5]pyrano[3,2-h]quinolines

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Paper | Regular issue | Vol 51, No. 6, 1999, pp.1321-1343
Published online:
DOI: 10.3987/COM-99-8494
2(3H)- and 2(5H)-Furanones. VII. Chirality Transfer on the Tetronic Acid Templates

Takefumi Momose, Naoki Toyooka,* Morihiro Nishio, Hiroyuki Shinoda, Hiromi Fujii, and Hironobu Yanagino

*Faculty of Pharmaceutical Sciences, Toyama Medical and Pharmaceutical University, 2630 Sugitani, Toyama, Toyama 930-0194, Japan

Abstract

The chirality transfer on the β-tetronic acid templates has been examined via highly diastereoselective alkylation or the Michael reaction at the α-position of the acids. Synthetic utility of this transfer procedure was demonstrated by the formal synthesis of (+)-cassiol and enantiodivergent synthesis of O-methyljoubertiamine.

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Paper | Regular issue | Vol 51, No. 6, 1999, pp.1345-1353
Published online:
DOI: 10.3987/COM-99-8500
Practical Synthesis of 2-Pyridone Core: Ethyl 8-Chloro-1-cyclopropyl-7-fluoro-9-methyl-4-oxo-4H-quinolizinone-3-carboxylate

Qun Li,* Thomas Sowin, Akiyo Claiborne, Linda Lijewski, Xiaolin Zhang, Kathleen Raye, Hormoz Mazdiyasni, William Arnold, Laura M. Melcher, Weibo Wang, Lisa Hasvold, Anthony Fung, Daniel T. W. Chu, and J. J. Plattner

*Pharmaceutical Product Division, Abbott Laboratories, D-47B, AP 10, 100 Abbott Park Road, Abbott Park, Illinois 60064-3500, U.S.A.

Abstract

A practical synthesis of the fluoropyridone core (2), an important intermediate to ABT-719 and other 2-pyridones, from the commercially available 3-chlorotetrafluoropyridine in 10 to 11 linear transformations with 10-26% overall yield is described.

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Paper | Regular issue | Vol 51, No. 6, 1999, pp.1355-1369
Published online:
DOI: 10.3987/COM-99-8502
Synthesis and Photochemistry of Styryl Substituted Annelated Furan Derivatives

Marija Sindler-Kulyk,* Irena Skoric, Slavica Tomsic, Zeljko Marinic, and Draginja Mrvos-Sermek

*Department of Organic Chemistry, Faculty of Chemical Engineering and Technology, University of Zagreb, Marulicev trg 19, P.O Box 177, HR-10000 Zagreb, Croatia

Abstract

New β-substituted benzo- and naphthofuryl derivatives (5, 6 and 7) of o-divinylbenzene, were synthesized and irradiated in order to form annelated bi-cyclo[3.2.1]octadienes. While 2-[2-(2-vinylphenyl)ethenyl]benzo[b]furan (5) upon irradiation gives the bicyclo[3.2.1]octadiene derivative (12) in 65% yield, 2-[2-(2-vinylphenyl)ethenyl]naphtho[2,1-b]furan (6) and 2-[2-(2-vinylphenyl)ethenyl]na-phtho[1,2-b]furan (7), undergo cis-trans-isomerization but not form intramole-cular photocycloaddition products. The mechanism of the intramolecular [2+2] photocycloaddition is explained via intermediate (17) which was proved by the formation of products (18) and (19), by irradiation in methanol and deuteromethanol.

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Paper | Regular issue | Vol 51, No. 6, 1999, pp.1371-1388
Published online:
DOI: 10.3987/COM-99-8503
Studies on Water-soluble Artificial Receptors Containing Chiral Side Chains Derived from Carbohydrates. 2. Formation of Diastereomeric Inclusion Complexes between Optically Active Cyclophane TCP44 and Chiral Aromatic Guests in Acidic Aqueous Solutions

Ichiro Takahashi,* Yuuko Aoyagi, Itsumi Nakamura, Akinao Kitagawa, Kazutsugu Matsumoto, Hidehiko Kitajima, Kimio Isa, Kazunori Odashima,* and Kenji Koga*

*Department of Applied Chemistry and Biotechnology, Faculty of Engineering, Fukui University, Bunkyo, Fukui-Shi 910-8507, Japan

Abstract

Systematic 1H NMR investigations on the formation of diastereomeric complexes of optically active cyclophane host TCP44 and chiral aromatic guests in acidic aqueous or mixed aqueous/methanolic solutions are described, Inclusion of chiral aromatic guests into the cavity led to enantiomeric splitting of the guest proton signals, particularly those of the protons near the chiral center. The chiral recognition was quantitatively evaluated for 1-hydroxy-arylacetic acids and 1-arylethanols on the basis of the stability constants and complexation shifts of 1:1 complexes, determined by 1H NMR titration experiments. A possible mode of chiral recognition is discussed.

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Paper | Regular issue | Vol 51, No. 6, 1999, pp.1389-1400
Published online:
DOI: 10.3987/COM-99-8504
Chemo- and Regioselective Syntheses of Enantiopure Aminopyrrolidinones as Building Blocks for Constrained Peptidomimetics

Thomas Lehmann, Dorothee Michel, Markus Glänzel, Reiner Waibel, and Peter Gmeiner*

*Lehrstuhl für Pharmazeutische Chemie, Institut für Pharmazie und Lebensmittelchemie, Universität Erlangen-Nüernberg,Schuhstrasse19, D-91052 Erlangen, Germany

Abstract

Starting from natural asparagine the synthesis of the N-protected enantiomerically pure 3- and 4-aminopyrrolidinones (1) and (3) was accomplished. The incorporation of these building blocks into conformationally constrained peptidomimetics was demonstrated by the synthesis of the potential dopamine receptor modulator (14b) (β-PAOPA). Furthermore, Freidinger γ-lactams including the protected dipeptide mimetics (8a-c) and (9) were prepared. The optical integrity of the synthesis was established by NMR analysis of the ureas (10a,b).

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Paper | Regular issue | Vol 51, No. 6, 1999, pp.1401-1407
Published online:
DOI: 10.3987/COM-99-8512
1,2-Dihydro-1,3,5-triazines from 1,3-Diaza-1,3-butadienes

Elisabetta Rossi,* Giorgio Abbiati, and Donatella Nava

*Instituto di Chimica Organica, Facoltà di Farmacia, Università degli Studi di Milano, Via Venezian 21, I-20133 Milano, Italy

Abstract

The 4-aryl-1-(4-methylphenyl)-2-phenyl- and 1-benzyl-2,4-diphenyl-1,3-diaza-1,3-butadienes are nearly quantitatively transformed into the corresponding 1,3,5-triazines when allowed to stand at room temperature in benzene solution. The mechanism of the reaction is discussed.

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Paper | Regular issue | Vol 51, No. 6, 1999, pp.1409-1420
Published online:
DOI: 10.3987/COM-99-8520
Cyano/Diallylamine Additions to Glycoside and Nucleoside Aldehydes and Its Application to the Synthesis of Polyoxin L and Uracil Polyoxin C

Kristina M. K. Kutterer* and George Just

*Steacie Institute for Molecular Sciences, National Research Council of Canada, 100 Sussex Drive, Ottawa, Ontario, K1A 0R6, Canada

Abstract

Three efficient, high yielding syntheses of precursors (1) of carbamoylpolyoxamic acid from L-arabinose, based on the simultaneous addition of the acid and amine functionalities, are described. Utilizing the same methodology and uridine as the starting material, an expedient 3 step (61% overall yield) synthesis of protected uracil polyoxin C (or the nucleoside moiety of polyoxin L, 2), is also described.

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Paper | Regular issue | Vol 51, No. 6, 1999, pp.1421-1426
Published online:
DOI: 10.3987/COM-99-8532
Highly Enantioselective Addition of Dialkylzincs to Aromatic Aldehydes Using 1-Phenyl-2-(1-pyrrolidinyl)-1-propanol as a Chiral Catalyst

Kenso Soai,* Takashi Konishi, and Takanori Shibata

*Department of Applied Chemistry, Faculty of Science, Science University of Tokyo, Kagurazaka 1-3, Shinjuku-ku, Tokyo 162-8601, Japan

Abstract

(1S,2R)- and (1R,2A)-1-phenyl-2-(1-pyrrolidinyl)-1-propanol catalyzes the enantioselective addition of dialkylzincs to aromatic aldehydes to afford enantiomerically enriched aromatic sec-a1coho1s with up to 92% enantiomeric excess.

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Note | Regular issue | Vol 51, No. 6, 1999, pp.1427-1431
Published online:
DOI: 10.3987/COM-99-8495
2(3H)- and 2(5H)-Furanones. VIII. Preparation and α Nucleophilicity of (S)-γ-Isopropyl-α-methyl-β-tetramic Acid

Naoki Toyooka,* Morihiro Nishio, Hiroyuki Shinoda, and Takefumi Momose

*Faculty of Pharmaceutical Sciences, Toyama Medical and Pharmaceutical University, 2630 Sugitani, Toyama, Toyama 930-0194, Japan

Abstract

An efficient preparation of (S)-γ-isopropyl-α-methyl-β-tetramic acid has been established, and the α nucleophilicity of the acid has been also examined

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Note | Regular issue | Vol 51, No. 6, 1999, pp.1433-1436
Published online:
DOI: 10.3987/COM-99-8507
Synthesis of Polycyclic Bismesoionic Compounds

Chok Wah Lo, Wing Lai Chan,* Yau Shan Szeto, and Chiu Wing Yip

*Department of Applied biology and Chemical Technology, The Hong Kong Polytechnic University, Hung Hom Kowloon, China

Abstract

Sydno[3,4-a] [1,3]thiazolo[2.3-c]quinoxal in-6-one was synthesized from readily available sydno[3,4-a]qu inoxalin-4-thione. In an attempted syntlies is of sydnonyl-1,2,4-thiadiazol-3-one, an unexpected dimer bissydno[3,4-a]quinoxalin-4-yl disulfide was obtained.

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Note | Regular issue | Vol 51, No. 6, 1999, pp.1437-1441
Published online:
DOI: 10.3987/COM-99-8510
An Interrupted Pummerer Reaction Induced by Hypervalent Iodine(III) Reagent: A New Synthesis of Pyrrolo[2,1-b]benzothiazole

Ling-Ching Chen,* Huey-Min Wang, and Iou-Jiun Kang

*Graduate Institute of Pharmaceutical Sciences, Kaohsiung Medical College, 100 Shih Chen 1st Rd., Kaohsiung 80708, Taiwan, R.O.C.

Abstract

Treatment of 1-(2-alkylthiophenyl)pyrroles with phenyliodine(III) bis(trifluoroacetate) containing trifluoroacetic acid resulted in an interrupted Pummerer reaction to give pyrrolo[2,1-b]benzothiazole rather than the normal Pummerer-type products.

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Review | Regular issue | Vol 51, No. 6, 1999, pp.1443-1470
Published online:
DOI: 10.3987/REV-98-514
Heterolignans

Angel C. Ramos, Rafael Peláez-Lamamié de Clairac, and Manuel Medarde*

*Departamento de Quimica Farmacéutica, Facultad de Farmacia. Universidad de Salamanca, Camupus "Miguel de Unamuno", Av. Campo Charro s.n., E-37007 Salamanca, Spain

Abstract

Lignans are natural bis-phenyipropanoids having biological activities. Fully synthetic analogues carrying heteroatoms instead of C atoms on the basic skeleton have been grouped under the name heterolignans. In this review a classification and their structures, biological activities and synthesis are presented.

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23 data found. 1 - 23 listed