Regular Issue

Vol. 31, No. 12, 1990

24 data found. 1 - 24 listed
Communication | Regular issue | Vol 31, No. 12, 1990, pp. 2091 - 2094
Published online:
DOI: 10.3987/COM-90-5576
Vinyloxyborane Promoted 1,4-Addition of Triethyl(1-methylindol-2-yl)borate to 2-Cycloalkenones

Minoru Ishikura and Masanao Terashima*

*Faculty of Pharmaceutical Scicences, Higashi-Nippon-Gakuen University, Ishikari-Tobetsu, Hokkaodo 061-02, Japan


The conjugate addition reaction of triethyl(1-methylindol-2-yl)borate to 2-cycloalkenone could be effected with a catalytic amount of vinyloxyborane.

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Communication | Regular issue | Vol 31, No. 12, 1990, pp. 2095 - 2098
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DOI: 10.3987/COM-90-5590
Ru(II)-Bipyridine Complex with Polyether Chain as a Bifunctional Catalyst for Epoxidation of Stilbene in a Biphasic System

Tatsuya Nabeshima,* Tadashi Inaba, and Naomichi Furukawa

*Department of Chemistry, Faculty of Engineering, Gunma University, 1-5-1 Tenjin-cho, Kiryu 376-8515, Japan


Polyether bearing bipyridine moieties at the ends of the chain was found to catalyze not only epoxidation of stilbene but also transfer of periodate salt as an oxidant between different liquid phases(H2O - CH2Cl2). Metal-ion dependent yield of the epoxide can be modulated by the polyether.

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Communication | Regular issue | Vol 31, No. 12, 1990, pp. 2099 - 2102
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DOI: 10.3987/COM-90-5592
Synthesis of a Thiomuscarone Analog

Gideon Shapiro* and Yair Lavi

*Preclinical Research, SANDOZ Pharma Ltd., CH-4002 Basle, Switzerland


A novel synthesis of the thiomuscarone analog, 1-thia-2,8-dimethyl-3-oxo-8-azaspiro[4.5]decane (4) has been achieved. Other thiolan-3-ones which are highly substituted in the 5-position should be available by this method which provides and alternative to the classical Michael reaction-Dieckmann sequence.

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Communication | Regular issue | Vol 31, No. 12, 1990, pp. 2103 - 2106
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DOI: 10.3987/COM-90-5596
Convenient and Selective Synthesis of 4-Trifluoromethylimidazoles

Yasuhiro Kamitori, Masaru Hojo,* Ryoichi Masuda, Yoshihiko Kawamura, and Xie Fand

*Department of Industrial Chemistry, Faculty of Engineering, Kobe University, Rokkodai-cho, Nada-ku, Kobe 657-8501, Japan


Thermally induced cyclization of 3-aryl-1,1,1-trifluoropropane-2,3-dione 2-dimethylhydrazones (5) which can be readily prepared from correspondign arenecarbaldehyde afforded selectively the title compounds (3) in high yields without formation of the regioisomers

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Communication | Regular issue | Vol 31, No. 12, 1990, pp. 2107 - 2110
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DOI: 10.3987/COM-90-5598
Regioselective Synthesis of Bicyclic Diselenides by the Reaction of Phosphonium Ylides with Elemental Selenium

Kentaro Okuma,* Isao Kaneko, Hiroshi Ohta, and Yoshinobu Yokomori

*Department of Chemistry, Faculty of Sciences, Fukuoka University, 8-19-1 Nanakuma, Jonan-ku, Fukuoka 814-0180, Japan


Selenabicyclo[2.2.1]heptense reacted with elemental selenium to produce unusual bicyclic diselenides in 30-40% yield. The reaction of phosphonium ylides with excess of elemental selenium also afforded bicyclic diselenides in good yields. The reactions might proceed via biradical intermediates.

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Communication | Regular issue | Vol 31, No. 12, 1990, pp. 2111 - 2114
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DOI: 10.3987/COM-90-5603
Study and Characterization of Tautomeric Triazolium Ylids

Axel Couture, Alain Lablache-Combier, Pierre Grandclaudon, and Gheorghe Surpateanu*

*Departement de Chimie, Institut Polytechnique de Iasi, Splai Bahlui Stg. 71, 6600 Iasi, Romania


The presence of two tautomeric forms in equilibrium for some triazolium ylids has been revealed by nmr spectroscopy and confirmed by trapping with picryl chloride.

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Communication | Regular issue | Vol 31, No. 12, 1990, pp. 2115 - 2119
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DOI: 10.3987/COM-90-5605
Regio- and Stereocontrols in the Photo[2+2]cycloaddition of 1,3-Dioxin-4-ones to Alkenes. Use of an Ester Group as the Connecting Unit in the Intramolecular Variant

Masayuki Sato,* Yoshito Abe, Hirohide Ohuchi, and Chikara Kaneko*

*Pharmaceutical Institute, Tohoku University, Aobayama, Sendai 980-8578, Japan


Intramolecular photo[2+2]cycloaddition of dioxinones to alkene to give eight membered lactones proceeds with complete stereo- and high regioslelctivities when an ester group presents as a linking unit between the acetal carbon and double bond of the side chain. The successful separation of some dioxinones into the enantiomers indicates the method is useful for synthesis of enantiomerically pure compounds.

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Communication | Regular issue | Vol 31, No. 12, 1990, pp. 2121 - 2124
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DOI: 10.3987/COM-90-5616
Chemical Modification of Erythromycins. VIII. A New Effective Route to Clarithromycin (6-O-Methylerythromycin A)

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

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


Selective O-methylation of the C-6 hydroxyl group of erythromycin A could be satisfactorily achieved by using its 9-oxime derivatives as the starting materials. Thus, 6-O-methylerythromycin A (clarithromycin) was synthesized from 2’-O,3’-N-bis(benzyloxycarbonyl)-N-demethylerythromycin A via its 9-oxime derivative by 6 step.

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Communication | Regular issue | Vol 31, No. 12, 1990, pp. 2125 - 2129
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DOI: 10.3987/COM-90-5618
Antimalarial Artemisinin Analogs: Synthesis of 2,3-Desethano-12-deoxoartemisinin-related Compounds

Yasuhiro Imakura,* Katsutoshi Hachiya, Tomomi Ikemoto, Shigeru Kobayashi, Shinsuke Yamashita, Jinsaku Sakakibara, Forrest T. Smith, and Kuo-Hsiung Lee

*Faculty of Sciences, Naruto University of Education, Takashima, Naruto-shi, Tokushima 772- , Japan


2,3-desethano-12-deoxoartemisinin-related compounds ((+)-16a) and ((-)-16b) have been synthesized from R-(+)-citronellal (7) by a stereoselective manner, which is applied to the synthesis of various novel antimalarial artemisinin analogs.

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Paper | Regular issue | Vol 31, No. 12, 1990, pp. 2131 - 2138
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DOI: 10.3987/COM-90-5513
Synthesis of Isoquino[1,2-b]quinazolines by Cycloaddition Reaction

Isabelle Kanmacher, Jean-Francois Stambach,* and Louis Jung

*Laboratoire de Chimie Thérapeutique, U.F.R. des Sciences Pharmaceutiques, Université Louis Pasteur, 74, route du Rhin, BP 24, 67401 ILLKIRCH Cedex, France


The cycloaddition reaction of 3,4-dihydroisoquinolinium salts (2c,d) with 2-aminobenzaldehydes (1a,b) was a convenient way to obtain 5,6,13,13a-tetrahydro-8H-isoquinol[1,2-b]quinazolium salts (3a-d). The reduction, transposition and oxidation of these compounds gave 8H-isoquino[1,2-b]quinazoline derivatives in good yields. The mechanism of the cycloaddition reaction is discussed. The cis and trans isomer of the tetrahydro derivative (5d) have been isolated and identified by an infrared spectroscopic study.

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Paper | Regular issue | Vol 31, No. 12, 1990, pp. 2139 - 2145
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DOI: 10.3987/COM-90-5541
Heterocyclizations of Thiosemicarbazones with α-Chloroacetyl Chloride

Shigeru Kabashima, Yasuhiro Tomita, Tadashi Ohkawara, Tetsuo Yamasaki, and Mitsuru Furukawa*

*Faculty of Pharmaceutical Sciences, Kumamoto University, 5-1 Oe-hon-machi, Kumamoto 862-0973, Japan


4-substituted thiosemicarbazones were allowed to react with α-chloroacetyl chloride to give two types of 1,3-thiazolin-4-ones which arose from the different cyclization depending on the substituents.

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Paper | Regular issue | Vol 31, No. 12, 1990, pp. 2147 - 2152
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DOI: 10.3987/COM-90-5542
Bridgehead Nitrogen Heterocycles. Part-II: Synthesis of Some Fused Heterocyclic Systems from 4-Amino-3-(2,4-dichlorophenyl)-5-mercapto-1,2,4-s-triazoles

Probin C. Gogoi and Jibon C. S. Kataky*

*Regional Reseach Labratory, Jorhat 785 006, India


The condensation reacton of 4-amino-3-(2,4-dichlorophenyl)-5-mercapto-1,2,4-s-triazole with aromatic carboxylic acids, aromatic aldehydes, ketones, diketones and α-haloketones leading to the formation of fused heterocycles was carried out.

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Paper | Regular issue | Vol 31, No. 12, 1990, pp. 2153 - 2161
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DOI: 10.3987/COM-90-5554
The Hantzsch Synthesis with 6-Aminouracils: One Step Synthesis of Pyrido[2,3-d]pyrimidines

Masahiro Kajino* and Kanji Meguro

*Chemistry Research Laboratories, Research and Development Division, Takeda Chemical Industries, Ltd., 17-85 Jusohonmachi 2-chome, Yodogawa-ku, Osaka 532-8686, Japan


A one-step synthesis of new pyrido[2,3-d]pyrimidine derivatives (III) was achieved through the Hantzsch synthesis using 6-aminouracils (I) as enamine nucleophiles.

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Paper | Regular issue | Vol 31, No. 12, 1990, pp. 2163 - 2172
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DOI: 10.3987/COM-90-5562
Synthesis of Aza Analogs of Amrinone

Baldev Singh* and George Y. Lesher

*Department of Medical Chemistry, Sterling Research Group, Rensselaer, New York 12144, U.S.A.


The aldol condensation product (4) of 4-acetylpyridine (2) and diethyl mesoxalate (3) was converted to pyridazinecarboxylic acid hydrazide (6). Curtius reaction of 6 gave aminopyridazinones (7). The condensation of (4-pyridinyl)glyoxal (17) with aminomalonamide (18) which was transformed to aminopyrazinone (19) by the Hofmann raction. Curtius reaction of 1,2,4-triazinone-5-carboxylic acid (21b) gave aminotriazinone (22). Demethylation of methoxypyrimidine (29) prepared from methyl 2-methoxyformylacetate (25) and isonicotinamidine (26) gave pyrimidinol (30).

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Paper | Regular issue | Vol 31, No. 12, 1990, pp. 2173 - 2179
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DOI: 10.3987/COM-90-5567
Components of the Bark of Artocarpus rigida Bl. 1. Structures of Two New Isoprenylated Flavones, Artonins G and H

Yoshio Hano, Ryohei Inami, and Taro Nomura*

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


From the bark of Artocarpus rigida Bl. (Moraceae), collected in Indonesia, two new isoprenylated flavones, artonins G (1) and H (2) were isolated along with three known isoprenylated flavones, artonin E (3), cycloartobiloxanthone (4), and artobiloxanthone (5). The structures of artonins G and H were shown to be 1 and 2, respectively, on the basis of spectroscopic data.

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Paper | Regular issue | Vol 31, No. 12, 1990, pp. 2181 - 2186
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DOI: 10.3987/COM-90-5572
Stereoselective Synthesis of (Z)-2,3-Dihydro-3-(arylmethylene)benzofurans via the Palladium Catalyzed Insertion and Cross Coupling Reaction of 1-Iodo-2-(2-propynyloxy)benzene and Arylzinc Chloride

Fen-Tair Luo* and Ren-Tzong Wang

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


The title compound was prepared in fair to good yields from 1-iodo-2-(2-propynyloxy)benezne and arylzinc chloride via tandem insertion and cross coupling reaction catalyzed by pertient palladium catalyst, such as palladium acetate and triphenylphosphine.

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Paper | Regular issue | Vol 31, No. 12, 1990, pp. 2187 - 2194
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DOI: 10.3987/COM-90-5582
Synthesis of 1,4,5-Trisubstituted Imidazoles

Alan R. Katritzky,* Jinlong Jiang, and Philip A. Harris

*Department of Chemistry, University of Florida, Gainesville, FL 32611-2046, U.S.A.


1-Substituted 4,5-diarylimidazoles are prepared in high yields by the reaction of 1-(benzotriazol-1-yl)-N-triphenylphosphorylidenemethylamine with primary amines and the treatment of the resulting intermediates with α-diaryl ketones.

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Paper | Regular issue | Vol 31, No. 12, 1990, pp. 2195 - 2199
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DOI: 10.3987/COM-90-5583
Lignans. 13. Total Synthesis of (-)-Carinol, (-)-Carissanol and (-)-Hydroxythujaplicatin Methyl Ether

Kenza Khamlach, Robert Dhal, and Eric Brown*

*Laboratoire de Synthèse Totale de Produits Naturels (URA CNRS 482), Faculté des Sciences, Route de Laval, BP 535, 72017 Le Mans, France


The title componds were obtained by α-hydroxylation of the corresponding optically active α,β-dibenzyl-γ-butyrolactones, followed by chemical reduction of the lactonic ring and/or catalytic hydrogenolysis of the O-benzyl protecting groups.

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Paper | Regular issue | Vol 31, No. 12, 1990, pp. 2201 - 2204
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DOI: 10.3987/COM-90-5588
Reduction of Hetero-aromatic Nitro Compounds with Baker’s Yeast

Mitsuhiro Takeshita* and Sachiko Yoshida

*Tohoku College of Pharmacy, 4-4-1 Komatsushima, Aoba-ku, Sendai 981, Japan


Reduction of nitro group on hetero-aromatics with baker’s yeast has been examined.

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Paper | Regular issue | Vol 31, No. 12, 1990, pp. 2205 - 2208
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DOI: 10.3987/COM-90-5589
Penaresin, a New Sarcoplasmic Reticulum Ca-Inducer from the Okinawan Marine Sponge Penares Sp.

Jun’ichi Kobayashi,* Jie-fei Cheng, Shosuke Yamamura, Takuma Sasaki, and Yasushi Ohizumi

*Faculty of Pharmaceutical Sciences, Hokkaido University, Sapporo, Hokkaido 060, Japan


A new bromoindole alklaoid, penaresin, has been isolated from the Okinawan marine sponge Penares sp. as a powerful Ca-inducer in sarcoplasmic reticulum and its structure was assigned by the spectral data.

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Paper | Regular issue | Vol 31, No. 12, 1990, pp. 2209 - 2218
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DOI: 10.3987/COM-90-5591
Synthesis and Reaction of 7-Bromo-2-(trifluoromethyl)-10-methylphenothiazine with Nitriles and Amines under Aryne-forming Conditions

Edward R. Biehl,* Susan DePaul, Subhash P. Khanapure, Jennifer L. Self, Upali Siriwardane, Stephen Taylor, Long D. Tran, and Matt A. Tschantz

*Department of Chemistry, Southern Methodist University, P.O. Box 750314, Dallas, TX 75275-0314, U.S.A.


The titled compound (3) was prepared by treating commercially available 3-(trifluoromethyl)phenothiazine successively with sodium hydride, methyl iodide, and N-bromosuccinimide, and its structure was ascertained by X-ray analysis. The reaction of 3 with certain aliphatic nitriles and LDA gave typical 7- and 6-addition products via aryne (4) in ratios of ca. 85:15, 5:6, respectively. However, treatment of 3 with certain primary and secondary amines and the corresponding lithiated amide afforded a single 7-aminated product (7) in good yields in each case. The reaction of 3 with various phenylacetonitriles and LDA gave mixtures containing an 7-addition product (10) and a 6-arylmethyl-7-cyano rearranged nitrile (11) in similar ratio of 85:15, respectively. The structure of 11 was assigned on the basis of the greater tendency for the repuisite adduct (12), obtained from anion addition to the less favored 4-position of 4, to participate in the TARA pathway than that for the adduct (13), formed from anion addition to the more favored 3-position. The greater regioselectively of amine additions to 4 as compared to those of nitriel anion additions is explained on the basis of the relative reactivities of the amine and nitrile anion nucleophiles.

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Paper | Regular issue | Vol 31, No. 12, 1990, pp. 2219 - 2224
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DOI: 10.3987/COM-90-5597
Oxidation Chemistry of cis-2-(3-Furylidene)ethanol

William E. Fristad and Leo A. Paquette*

*Evans Chemical Laboratories, The Ohio State University, 120 W. 18th Avenue, Columbus, Ohio 43210, U.S.A.


Submission of the tri-n-butylstannylmethyl ether (9) of furylcarbinol (8) to Still rearrangement leads stereoselectively to 10 as the exclusive product. The cis-oriented nature of the hydroxyethyl and 3-furyl functional groups in 10 is cause for ready ring closure either to bensofuran (10) or lactone (13) depending upon conditions.

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Paper | Regular issue | Vol 31, No. 12, 1990, pp. 2225 - 2230
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DOI: 10.3987/COM-90-5615
C-Nucleosides. 15. Novel Ring Transformation of 6-Hydroxy-6-(2,3,5-tri-O-benzoyl-β-D-ribofuranosyl)-2,6-dihydropyran-3-one with Amidines to Imidazole

Isamu Maeba,* Kazuya Osaka, and Chihiro Ito

*Faculty of Pharmacy, Meijo University, 150 Yagotoyama, Tempaku, Nagoya 468-8503, Japan


The novel ring transformation of 6-hydroxy-6-(2,3,5-tir-O-benzoyl-β-D-ribofuranoxyl)-2,6-dihydropyran-3-one (1) with amidines to imidazole is described. Treatment of 1 with benzamidine afforded 3-[2-phenyl-4-(2,3,5-tri-O-benzoyl-β-D-ribofuranoxyl)imidazolyl]-2-oxo-1-propanol (2) in 53% yield. Treatment of 1 with O-methylisourea afforded 2-methoxyimidazole (3) in 27% yield. Treatment of 1 with acetamidine afforded 2-methylimidazole (4) in 10% yield. However, debenzoylation of 3 and 4 with alkaline did not afforded the deprotected imidazole C-nucleosides.

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Review | Regular issue | Vol 31, No. 12, 1990, pp. 2231 - 2266
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DOI: 10.3987/REV-90-418
Reactions of Chlorocyclophosphazenes with Difunctional Reagents

Vadapalli Chandrasekhar,* Madaligar Gopalakrishan Rao Muralidhara, and Iykkiam Immanuel Selvaraj

*Department of Chemistry, Indian Institute of Technology, Kanpur 208016, India


The reactions of chlorocyclophosphazenes with aliphatic and aromatic difunctional reagents are described. The reaction pathways involved, product preferences and stability of products are discussed. Structural data including 31P nmr parameters and X ray crystallographic data are presented.

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24 data found. 1 - 24 listed