Regular Issue

Vol. 34, No. 6, 1992

19 data found. 1 - 19 listed
Communication | Regular issue | Vol 34, No. 6, 1992, pp.1075-1083
Published online:
DOI: 10.3987/COM-92-6005
Giganenin, a Highly Potent Monotetrahydrofuran Acetogenin and 4-Deoxygigantecin from Goniothalamus giganteus

Xin-Ping Fang, Jon E. Anderson, David L. Smith, Karl V. Wood, and Jerry L. McLaughlin*

*Department of Medicinal Chemistry and Pharmacognosy, School of Pharmacy and Pharmacal Sciences, Purdue University, West Lafayette, IN 47907, U.S.A.

Abstract

Giganenin, a novel monotetrahydrofuran acetogenin with a double bond along the hydrocarbon chain, and 4-deoxygigantecin, a new nonadjacent bistetrahydrofuran acetogenin, have been isolated from the bark of Goniothalamus giganteus (Annonaceae) by the use of brine shrimp lethality for bioactivity-directed fractionation. The structures were elucidated based on spectral and chemical methods. Giganenin, which shows selective and highly potent cytotoxicities to human tumor cells in culture (ED50 values as low as 5.80 x 10-8 μg/ml) and toxicity to brine shrimp, is the most cytotoxic of the monotetrahydrofuran acetogenins reported thus far. 4-Deoxygigantecin is also cytotoxic to human tumor cells and toxic to brine shrimp.

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Communication | Regular issue | Vol 34, No. 6, 1992, pp.1085-1088
Published online:
DOI: 10.3987/COM-92-6015
Preparation of 2,5-Disilylated Thiophene Derivatives and Their Conversion to 2,5-Dihalo Derivatives

Naomichi Furukawa,* Hiroki Hoshiai, Tadao Shibutani, Masato Higaki, Fujiko Iwasaki, and Hisashi Fujihara

*Department of Chemistry, University of Tsukuba, Tsukuba, Ibaraki 305, Japan

Abstract

2,5-Disilylated thiophenes were prepared and readily oxidized with m-chloroperbenzoic acid (m-CPBA) to give the corresponding 1,1-dioxides. The thiophene dioxide was converted to 2,5-dihalogenothiophene dioxides with halogenating agents.

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Communication | Regular issue | Vol 34, No. 6, 1992, pp.1089-1092
Published online:
DOI: 10.3987/COM-92-6023
Total Synthesis of Eupomatidines-1,2, and 3

Yoshiyasu Kitahara and Akinori Kubo*

*Meiji College of Pharmacy, 1-35-23 Nozawa, Setagaya-ku, Tokyo 154, Japan

Abstract

Three aromatic alkaloids, eupomatidines-1 (1a), 2 (1b) and 3 (1c), were synthesized from the corresponding 1,4-naphthoquinones (2a, b) by hetero Diels-Alder reaction with 2-butenal dimethylhydrazones (3a, b), followed by one pot annelation of ring A.

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Communication | Regular issue | Vol 34, No. 6, 1992, pp.1093-1096
Published online:
DOI: 10.3987/COM-92-6034
A Breakthrough for the Photochemical Arylation in the 3-(Phenylmethyl)-2(5H)-furanone system Leading to the Tetrahydroindenofuranone System

Osamu Muraoka,* Genzoh Tanabe, Kyoko Sano, and Takefumi Momose*

*Faculty of Pharmaceutical Sciences, Kinki University, Kowakae 3-4-1, Higashi-osaka 577, Japan

Abstract

The photochemistry of the ’central methane’-substituted 3-benzyl-2(5H)-furanone system (1) is described. Despite its di-π-methane structure, photochemical arylation was found to predominate in place of the di-π-methane rearrangement, and gave substituted tetrahydroindenofuranones (2) in good yields.

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Communication | Regular issue | Vol 34, No. 6, 1992, pp.1097-1100
Published online:
DOI: 10.3987/COM-92-6036
A Novel and Efficient Synthesis of 9-(c-4,t-5-Bishydroxymethylcyclopent-2-en-r-1-yl)-9H-adenine (BCA) Having Anti-HIV Activity from Norbornadiene

Nobuya Katagiri,* Hiroshi Sato, Sachie Arai, Akemi Toyota, and Chikara Kaneko

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

Abstract

9-(c-4, t-5-Bishydroxymethylcyclopent-2-en-r-1-yl)-9H-adenine (BCA: 1), a novel carbocyclic nucleoside having significant anti-HIV activity, has been synthesized from norbornadiene.

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Paper | Regular issue | Vol 34, No. 6, 1992, pp.1101-1106
Published online:
DOI: 10.3987/COM-91-5957
Tetracyclic Indole Derivatives from the Reaction of Methyl 2,4-Dioxo-6,6-dimethoxyhexanoate with Tryptamine: Indolo[2,3-a]quinolizidine vs 3,7a-Diazacyclohepta[jk]fluorene

Jean-Yves Laronze,* Jacqueline Laronze, F. Wemba-Lenga, and Jean Lévy

*Laboratoire de Transformations et Synthèse deSubstances Naturelles, associé au CNRS, Université de Reims, Faculté de Pharmacie, 51 rue Cognacq-Jay, 51096 Reims, France

Abstract

Depending on the acid used for cyclization, reaction of methyl 6,6-dimethoxy-2,4-dioxohexanoate (4) with tryptamine yielded indoloquinolizidine (8) (AcOH) or diazacycloheptafluorene (10) (TFA). Treatment of 8 with TFA gave 10.

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Paper | Regular issue | Vol 34, No. 6, 1992, pp.1107-1117
Published online:
DOI: 10.3987/COM-92-5971
A Facile Synthesis of 9-Nor-9-hydroxyhexahydrocannabinol via Intramolecular Reverse Electron Demand Diels-Alder Cyclization

Zhan Guo Lu and Seiichi Inoue*

*Department of Synthetic Chemistry, Faculty of Engineering, Yokohama National University, Tokiwadai, Hodogaya-ku, Yokohama 240, Japan

Abstract

A simple and efficient new synthesis of 9-nor-9-hydroxyhexahydrocannabinol is achieved, through the intramolecular [4+2] cycloaddition of an o-quinonemethide which is generated from 2-(1-hydroxy-3-methoxymethoxy-7-methyl-6-octenyl)-1,3-bis(O-methoxymethyl)olivetol (12b), which in turn is prepared by reaction of the lithiated olivetol bis(methoxymethyl)ether with 3-methoxymethoxy-7-methyl-6-octenal (9).

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Paper | Regular issue | Vol 34, No. 6, 1992, pp.1119-1132
Published online:
DOI: 10.3987/COM-92-5996
Synthesis of Sulfur and Selenium Analogues of Psoralen

E. Andreas Jakobs, Léon E. Christiaens, and Marcel J. Renson*

*Université de Liège, Chimie Organique Hétérocyclique, Bat. B6. Sart Tilman 4000 Liège, Belgium

Abstract

7H-Thieno[3,2-g][1]benzothiopyran-7-one (1a), 7H-selenopyrano[3,2-f][1]benzothiophen-7-one (1b), 2H-selenolo[3,2-g][1]benzothiopyran-2-one (1c), 7H-selenolo[3,2-g][1]benzoselenopyran-7-one (1d) have been synthesized.

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Paper | Regular issue | Vol 34, No. 6, 1992, pp.1133-1145
Published online:
DOI: 10.3987/COM-92-6000
Heterocyclic Compounds. I. Reactions of o-Amino-carboxamide with β-Diketones: Synthesis of Imidazo[1,5-a]pyrimidine and Pyrazolo[1,5-a]pyrimidine Derivatives

Ji-Wang Chern,* Chung-Chi Lee, Yen-Chywan Liaw, and Andrew H.-J. Wang

*Institute of Pharmacy and Medical Laboratories, National Defense Medical Center, P.O. Box 90048-512, Taipei, Taiwan, R.O.C.

Abstract

Treatement of 5-aminoimidazolo-4-carboxamide hydrochloride (1) and 5-aminopyrazole-4-carboxamide hemisulfate (2) with β-diketones furnished 2,4-disubstituted imidazo[1,5-a]pyrimidine-8-carboxamide (7) and 5,7-disubstituted pyrazolo[1,5-a]pyrimidine-3-carboxamide (8) respectively. The 1H nmr and 13C nmr spectra of these compounds and the X-ray crystallography of compound 7a are discussed.

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Paper | Regular issue | Vol 34, No. 6, 1992, pp.1147-1167
Published online:
DOI: 10.3987/COM-92-6004
Stereospecific Synthesis of a Ribosyl-diazepanone Derivatives; a Synthetic Approach for Elucidation of the Stereochemistry of a Lipid Nucleoside Antibiotic Liposidomycin B

Marianne R. Spada, Makoto Ubukata,* and Kiyoshi Isono

*Antibiotics Laboratory, RIKEN(The Institute of Physical and Chemical Research), Wako-shi, Saitama 351-01, Japan

Abstract

A new type of ribosyl-diazepanone derivative (23), the core ribosyl 7-membered heterocycle of the nucleoside antibiotic liposidomycin B has been synthesized using a chiral synthetic route that could offer accessibility to any of possible stereoisomers of 23. Starting from readily available cis-1,4-butenediol and β-D-ribose, epoxides (4) and (14) were obtained. Regioselective nucleophillic ring opening of these epoxides subsequently to the several reaction steps afforded key intermediates amine (9) and azido acid (19) which were ultimately coupled to furnish amide (20). During hydrogenolysis of azido aldehyde (22) an intramolecular Schiff base formation occurred yielding the desired product (23).

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Paper | Regular issue | Vol 34, No. 6, 1992, pp.1169-1175
Published online:
DOI: 10.3987/COM-92-6009
Synthesis of Some 5-Substituted Indoles

Youhua Yang, Arnold R. Martin,* David L. Nelson, and John Regan

*Department of Pharmaceutical Sciences, College of Pharmacy, University of Arizona, Tucson, AZ 85721, U.S.A.

Abstract

A halogen-metal exchange strategy was employed to prepare several 5-substituted indoles from 5-bromoindole. Additional derivatives were elaborated from the formyl, acetyl, thiomethyl, boronic acid and trimethylstannyl analogues thus prepared.

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Paper | Regular issue | Vol 34, No. 6, 1992, pp.1177-1182
Published online:
DOI: 10.3987/COM-92-6010
Oxidative Coupling of 4-Substituted N,N-Dimethylanilines with Cyclic Vinyl Ethers in the Presence of Either Manganese(II) or Cobalt(II) Nitrate under Oxygen

Satoru Murata, Koji Teramoto, Masahiro Miura,* and Masakatsu Nomura

*Department of Applied Chemistry, Faculty of Engineering, Osaka University, Suita, Osaka 565, Japan

Abstract

The reaction of 4-substituted N,N-dimethylanilines with 2,3-dihydrofuran and 3,4-dihydro-2H-pyran proceeds in the presence of a catalytic amount of manganese(II) or cobalt(II) nitrate under oxygen to give the corresponding hexahydrofuro- and hexahydro-2H-pyrano[3,2-c]quinolines, respectively.

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Paper | Regular issue | Vol 34, No. 6, 1992, pp.1183-1190
Published online:
DOI: 10.3987/COM-92-6012
Thermolysis of 1,2,3-Triazines

Takashi Itoh, Mamiko Okada, Kazuhiro Nagata, and Akio Ohsawa*

*School of Pharmaceutical Sciences, Showa University, 1-5-8 Hatanodai, Shinagawa-ku, Tokyo 142, Japan

Abstract

Thermal reactions of 1,2,3-triazines were investigated using neat thermolysis and flash vacuum thermolysis (FVT). Neat thermolysis afforded the products which were derived from intermolecular reaction, whereas unimolecular degradation occurred by FVT to give alkyne, nitrile and nitrogen. The selectivity of the reaction was considered using molecular orbital calculations.

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Paper | Regular issue | Vol 34, No. 6, 1992, pp.1191-1200
Published online:
DOI: 10.3987/COM-92-6016
Thieno[3,4-b][1,4]diazepines: Synthesis and Stereochemistry

Alba Chimirri, Rosaria Gitto, Silvana Grasso, Giovanni Romeo, and Maria Zappalà

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

Abstract

The synthesis of 1,3-dihydro-2H- and 2,3,4,5-tetrahydro-1H-thieno[3,4-b][1,4]diazepine derivatives from 3,4-diaminothiophene and β-keto esters is described.

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Paper | Regular issue | Vol 34, No. 6, 1992, pp.1201-1211
Published online:
DOI: 10.3987/COM-92-6017
A Synthesis of 4-Cyano-hexahydro-2H-benzo[b]quinolizine-7,10-dione as a Simple Model Compound of Saframycin A

Akinori Kubo,* Tatsuya Nakai, Yuichi Koizumi, Naoki Saito, Yuzuru Mikami, Katsukiyo Yazawa, and Jun Uno

*Meiji College of Pharmacy, 1-35-23 Nozawa, Setagaya-ku, Tokyo 154, Japan

Abstract

A simple and efficient synthesis of 4-cyano-8-methoxy-9-methyl-1,3,4,6,11,11a-hexahydro-2H-benzo[b]quinolizine-7,10-dione (20a) as a simple model compound of saframycin A (1) is described starting from the corresponding lactam (16). Reduction of the lactam (16) with lithium aluminum hydride followed by sodium cyanide treatment afforded the α-amino nitrile (19) as an inseparable mixture in an excellent yield. Oxidative demethylation of compound (19) with 10N HNO3 gave the title compound (20a) and its C-4 epimer (20b). The structure of 20a was confirmed by 1H nmr and 13C nmr spectroscopic analysis.

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Paper | Regular issue | Vol 34, No. 6, 1992, pp.1213-1225
Published online:
DOI: 10.3987/COM-92-6026
1H Nmr Chemical Shift of the Flavonol 5-Hydroxy Proton as a Characterization of 6- or 8-Isoprenoid Substitution

Toshio Fukai and Taro Nomura*

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

Abstract

1H Nmr examination of 6- or 8-isoprenoid substituted flavonols has shown that the location of isoprenoid side chain on A ring can be deduced from the chemical shift of the 5-hydroxy proton. The application of this 1H nmr technique to identification of the isoprenoid substituted flavonols is discussed. The proposed structures for glepidotin A and two flavonols were revised with this method as well as chemical method.

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Paper | Regular issue | Vol 34, No. 6, 1992, pp.1227-1230
Published online:
DOI: 10.3987/COM-92-6029
The Synthesis of Tetrapyranozole Substitued Phenols

Mitchell R. Malachowski,* Marilyn G. Davidson, and J. Daniel Davis

*Department of Chemistry, University of San Diego, San Diego, C.A. 92110, U.S.A.

Abstract

The synthesis of two new potentially dinucleating tetrapyrazole substituted phenols is described. The compounds 2,6-bis[(bis(pyrazol-1-ylmethyl)amino)methyl]phenol (1) and 2,6-bis[(bis(3,5-dimethylpyrazol-1-ylmethyl)amino)methyl]phenol (2) were prepared via the pyrazolylmethylation of amines.

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Paper | Regular issue | Vol 34, No. 6, 1992, pp.1231-1238
Published online:
DOI: 10.3987/COM-92-6032
Studies on the Alkaloids from Aconitum contortum (II)

Kazuaki Niitsu,* Yukinobu Ikeya, Takao Katsuhara, Hiroshi Mitsuhashi, Liang Huiling, and Chen Siying

*Research Institute for Biology & Chemistry, TSUMURA & CO., 3586 Yoshiwara, Ami-machi, Inashiki-gun, Ibaraki 300-11, Japan

Abstract

Three new diterpenoid alkaloids, contorine (1), contortine (2) and contorsine (3) were isolated from the roots of Aconitum contortum. Structures of these alkaloids were determined on the basis of spectral data and X-ray analyses.

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Paper | Regular issue | Vol 34, No. 6, 1992, pp.1239-1249
Published online:
DOI: 10.3987/COM-92-6035
An Investigation of the Influence of Haloarenes and Hetarylacetonitriles on the Competition between Possible Aryne Arylation and Tandem Addition-Rearrangement Pathways

A. Rakeeb Deshmukh, Matt Morgan, Long Tran, Hongming Zhang, Mahesh Dutt, and Edward R. Biehl*

*Department of Chemistry, Southern Methodist University, Dallas, Texas 75275, U.S.A.

Abstract

Attempts to extend the LDA-mediated 1-aminoisoquinoline arynic synthesis to 1,2-dibromo-3,4,5,6-tetramethylbenzene (1a) and the hetarylacetonitriles 2-(2a) and 3-pyridylacetonitrile (2b), 2- (2c) and 3-thiophene acetonitrile (2d), and 2-benzimidizoylacetonitrile (2e) failed; only rearranged 2-hetarylmethyl-3,4,5,6-tetramethylbenzonitriles (3aa-ae) were obtained. Additionally, the reaction of 1-chloro-2,5-dimethylbenzene (1b), 2-bromo-4-methylanisole (1c), bromobenzene (1d), 2-bromoanisole (1e), and 1-bromo-2,5-dimethoxybenzene (1f) with 2a-e gave rearranged nitriles (3) by the tandem addition-rearrangement aryne pathway and/or aryne arylated nitriles (4) by the aryne arylation pathway. By evaluating product 3:4 ratios from these reactions, an assessment of the influence of the nature of the haloarenes and hetarylacetonitriles on the competing tandem addition-rearrangement and aryne arylation pathways was made, which showed that the preference of the haloarenes for the rearrangement pathway to be 1a ~ 1b>1c > 1d>1e>1f and that for the hetarylacetonitriles to be 2c ~ 2d>2b>2a>2e. An explanation in terms of the influence of the haloarene substituents on the ring-closure step of the rearrangement pathway and the heterocyclic ring of the hetarylacetonitrile on the proton abstraction step of the alternate aryne arylation pathway is presented.

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19 data found. 1 - 19 listed