Regular Issue

Vol. 68, No. 2, 2006

18 data found. 1 - 18 listed
Communication | Regular issue | Vol 68, No. 2, 2006, pp.233-236
Published online: 20th December, 2005
DOI: 10.3987/COM-05-10632
Synthesis of (S)-Plakolide A and Revision of the Absolute Stereochemistry of the Natural (-)-Plakolide A

Masaru Kanayama, Keiji Nishiwaki, and Keizo Matsuo*

*Faculty of Pharmaceutical Sciences, Kinki University, 3-4-1, Kowakae, Higashi-Osaka 577-8502, Japan

Abstract

(S)-Plakolide A, a γ-lactone from the marine sponge Plakortis sp., was synthesized starting from (S)-lactic acid by applying the chiral self-reproduction procedure. As the results of the synthetic research, the absolute stereochemistry of the natural product should be revised to R.

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Paper | Regular issue | Vol 68, No. 2, 2006, pp.237-245
Published online: 17th January, 2006
DOI: 10.3987/COM-05-10581
Synthesis of Some Benzo-14-crown-4 Ethers Substituted to 7,8-Dihydroxy-3-phenylcoumarin Derivatives

Ümit Salan and Mustafa Bulut*

*Department of Chemistry, University of Marmara, Kadiköy-Istanbul, 34722, Turkey

Abstract

7,8-Dihydroxy-3-phenylcoumarin derivatives reacted with 1,2-bis-(3-tosyloxypropoxy)benzene in CH3CN/alkali carbonate to furnish 3-phenylchromenone-14-crown-4 ether derivatives, which were identified with elemental analysis, IR, 1H NMR, 13C NMR and MS spectroscopy.

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Paper | Regular issue | Vol 68, No. 2, 2006, pp.247-255
Published online: 13th December, 2005
DOI: 10.3987/COM-05-10591
Isolation, Structure Elucidation, and Syntheses of Isoneocryptotanshinone II and Tanshinlactone A from Salvia miltiorrhiza

Chang-Ming Sun, Tsung-Mei Chin, Yun-Lian Lin, Chien-Jui Chen, Wei-Chou Chen, Tian-Shung Wu, and Ming-Jaw Don

*National Research Institute of Chinese Medicine, 155-1, Sec. 2, Li-Nung Street, Taipei 112, Taiwan, R.O.C.

Abstract

Two new components, isoneocryptotanshinone II (1) and tanshinlactone A (2), were isolated from an EtOH extract of Salvia miltiorrhiza. The structures of 1 and 2 were established by spectroscopic methods and total syntheses. Compound (2) exhibited moderate cytotoxic activities with a CD50 range of 6.87-8.85 μg/mL against the HeLa (cervical epitheloid carcinoma), HepG2 (hepatocellular carcinoma) and OVCAR-3 (ovarian adenocarcinoma) cell lines.

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Paper | Regular issue | Vol 68, No. 2, 2006, pp.257-270
Published online: 13th December, 2005
DOI: 10.3987/COM-05-10603
Synthesis of Vinca Alkaloids and Related Compound 103. Recognition of an Unexpected Reaction and Its Application in Building the Aspidospermane Skeleton. Simple Synthesis of 15β-Hydroxyvincadifformine

György Kalaus,* Flórián Tóth, István Greiner, Mária Kajtár-Peredy, Ágnes Gömöry, László Hazai, and Csaba Szántay*

*Department of Organic Chemistry,Research Group for Alkaloid Chemistry fo the Hungarian Academy of Sciences, Budapest University o f Technical Economics, Hungary

Abstract

Reaction of tryptamine derivative (2b) and acetate ester (11) built up from 2-(chloromethylene)butanal (4) resulted in enamino ketone (14). Dehydration of 14 and subsequent intramolecular [4+2] cycloaddition led to 15-oxovincadifformine (15). Regio- and stereoselective reduction of the latter molecule supplied 15β-hydroxyvincadifformine (1).

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Paper | Regular issue | Vol 68, No. 2, 2006, pp.271-282
Published online: 13th December, 2005
DOI: 10.3987/COM-05-10612
Formal Synthesis of (±)-Hop ether, (±)-Isoboonein and (±)-Iridomyrmecin

Meng-Yang Chang,* Chun-Yu Lin, Bor-Fng Chen, and Nein-Chen Chang*

*Department of Applied Chemistry, National University of Kaohsiung, No. 700 Kaohsiung University Rd., Nan-Tzu District, Kaohsiung 811, Taiwan, R.O.C.

Abstract

A general synthesis of (±)-hop ether (5), (±)-isoboonein (6), and (±)-iridomyrmecin (7) from bicyclo[2.2.1]ketone (9) is described. Cyclopentenoid aldehyde (10) and bicyclo[3.2.1]lactone (11) are the key intermediates.

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Paper | Regular issue | Vol 68, No. 2, 2006, pp.283-294
Published online: 16th December, 2005
DOI: 10.3987/COM-05-10624
Conformations of 2,2’-Bipyrrole π-Systems Having an Electron-donating Site at One Terminal and Electron-accepting Site at the Other Terminal in the Ground and Excited States

Shoji Matsumoto, Takamitsu Kobayashi, and Katsuyuki Ogura*

*Deaprtment of Applied Chemistry and Biotechnology, Faculty of Engineering, Chiba University, 1-33 Yayoi-cho, Inage-ku, Chiba 263-8522, Japan

Abstract

Various symmetrical and unsymmetrical 1,1’,5,5’-tetraaryl-2,2’-bipyrroles (1, 5, and 10) were synthesized. From their UV-VIS absorption and fluorescence spectra, the conformations of the central 2,2’-bipyrrole systems were considered as follows. These compounds adopt twisted conformations in the ground state, but their conformations in the excited state are close to planar ones. Especially, the compounds (10) bearing a formyl group and an electron-donating methoxy group showed large Stokes shifts (~160 nm), suggesting effective conjugation through the π-system, which consists of the central 2,2’-bipyrrole, 5-aryl group, and 5’-aryl group, in the excited state.

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Paper | Regular issue | Vol 68, No. 2, 2006, pp.295-306
Published online: 17th January, 2006
DOI: 10.3987/COM-05-10629
A Facile Synthesis of Substituted 1,8-Naphthyridines Based on the Aza-Wittig/Electrocyclic Ring Closure Strategy

Carmen Veiga, José Ma Quintela,* Carlos Peinador,* Marcos Chas, and Antonio Fernández

*Department of Fundamental Chemistry, Faculty of Sciences, University of A Coruña, Campus A Zapateira, E-15071, A Coruña, Spain

Abstract

Several new 1,8-naphthyridine derivatives (7) and (8) has been synthesized via an aza-Wittig reaction. Iminophosphoranes, 2-ethoxy-3-cyano-5-(2-ethoxycarbonyl)-4-phenyl-6-[(triphenylphosphoranilidene)amino]pyiridine (4) and 2-ethoxy-3-cyano-5-(2-cyanovinyl)-4-phenyl-6[(triphenylphosphoranilidene)- amino]pyridine (5), easily obtained from the 2-chloro-5-cyano-6-ethoxy-4-phenylpyridine-3-carboxaldehyde (1), react with heterocumumulenes such as aromatic isocyanates to give directly the title compounds in an aza-Wittig/electrocyclic ring closure process. The yields were from 60% to 97%.

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Paper | Regular issue | Vol 68, No. 2, 2006, pp.307-321
Published online: 17th January, 2006
DOI: 10.3987/COM-05-10633
Designing Fluorous Domains. Synthesis of a Series of Pyridinium Salts Bearing a Perfluoroalkylated Azole Moiety

Ivana Pibiri, Andrea Pace, Silvestre Buscemi, Nicolò Vivona,* and Luciana Malpezzi

*Department of Organic Chemistry “E. Paternò”, University of Palermo, Viale delle Scienze Parco D’Orleans II, I-90128 Palermo, Italy

Abstract

The synthesis of a series of N-methylpyridinium salts bearing a perfluoroalkylated 1,2,4-oxadiazole or 1,2,4-triazole moiety is reported. X-Ray structures of representative perfluoroalkyl-triazolylpyridine (15) and methyl-pyridinium iodide salt (5a) are reported. Their crystal packing clearly shows segregation between the aromatic and parallel double layer fluorinated regions.

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Paper | Regular issue | Vol 68, No. 2, 2006, pp.323-330
Published online: 17th January, 2006
DOI: 10.3987/COM-05-10640
Chemoenzymatic Synthesis of Naturally Occurring Geranyl 6-O-Glycosyl-β-D-glucopyranosides

Eiji Kawahara, Mikio Fujii, Yoshiteru Ida, and Hiroyuki Akita*

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

Abstract

Direct β-glucosidation between geranyl alcohol and D-glucose (4) using the immobilized β-glucosidase from almonds with the synthetic prepolymer ENTP-4000 gave geranyl O-β-D-glucoside (1) in 11% yield. The coupling of the geranyl O-β-D-glucopyranoside congener (7) with 2,3,4-tri-O-benzoyl-α-D-xylopyranoside bromide (8) or 2,3,4-tri-O-benzoyl-α-L-arabinopyranosyl bromide (10) afforded the coupled products (9 and 11), respectively. Deprotection of the coupled products (9 and 11) using MeONa in MeOH-THF gave the synthetic geranyl 6-O-β-D-xylopyranosyl-β-D-glucopyranoside (2) and geranyl 6-O-α-L-arabinopyranosyl-β-D-glucopyranoside (Kenposide A, 3).

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Note | Regular issue | Vol 68, No. 2, 2006, pp.331-338
Published online: 16th December, 2005
DOI: 10.3987/COM-05-10587
A New Catalytic Application of a Keggin Acid in the Synthesis of Symmetrical Bis(indolyl)alkanes

Manas Chakrabarty,* Ajanta Mukherji, Sulakshana Karmakar, Shiho Arima, and Yoshihiro Harigaya

*Department of Chemistry, Bose Institute, 93/1, A. P. C. Road, Kolkata-700009, India

Abstract

Silicotungstic acid, H4SiW12O40, an important Keggin heteropoly acid, efficiently catalysed the reaction of indoles with aryl aldehydes in ethyl acetate solution at room temperature to furnish symmetrical bis(indolyl)alkanes expeditiously.

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Note | Regular issue | Vol 68, No. 2, 2006, pp.339-345
Published online: 20th December, 2005
DOI: 10.3987/COM-05-10598
Two Isoquinolones from the Roots of Phellodendron amurense var. wilsonii

Yu-Lung Chiang, Chung-Ren Su, Ping-Chung Kuo, Amooru G. Damu, and Tian-Shung Wu*

*Department of Chemistry, National Cheng Kung University, 1, Ta-Shiueh Rd., Tainan, 70101, Taiwan, R.O.C.

Abstract

Two isoquinolones, anhydroberberillic acid (1) and methyl anhydroberberillate (2) were isolated first time from the roots of Phellodendron amurense var. wilsonii as well as two related known compounds, berberine (3) and 8-oxyberberine (4). Their structures were elucidated by extensive 1D, 2D NMR and MS spectral analysis. Occurrence of the isoquinolones and protoberberines in the same plant indicated the definite possibility of these metabolites biogenetically originated from berberine alkaloids.

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Note | Regular issue | Vol 68, No. 2, 2006, pp.347-355
Published online: 27th December, 2005
DOI: 10.3987/COM-05-10609
Synthesis and Biological Evaluation of Benzothiazole Derivatives of Pyrimidines, Acrylonitriles, and Coumarins

Amal M. Youssef, Hany M. Mohamed, Caitlin Czezowski, Athar Ata, and Alaa S. Abd-El-Aziz*

*Department of Chemistry, The University of Winnipeg, 515 Portage Avenue, Winnipeg, Manitoba, R3B 2E9, Canada

Abstract

A number of benzothiazole derivatives of 2-aminopyrimidines (3a-b, 5, 6a-b, and 7), benzothiazole-3-arylacrylonitriles (10a-c), and benzothiazol-2-yl-coumarins (18a c, and 20) were synthesized by reacting benzothiazole derivatives with dicarbonyl compounds, and aromatic aldehydes. The unexpected 2-(4-methoxyphenyl)benzo[d]thiazole (14) was obtained as a unique product via the reaction of 2-aminothiophenol with ethyl 3-(4-methoxyphenyl)-2-scyanoacrylate. 2-(Benzo[d]thiazol-2-yl)-3-(4-hydroxyphenyl)acrylonitrile (10a) exhibited activity against Staphylococcus aureus. 2-(Benzo[d]thiazol-2-ylamino)pyrimidine-4,6-(1H,5H)-dione (3b) showed antibacterial activity selectivity against Corynebacterium xerosis. 2-(Benzo[d]thiazol-2-ylamino)-6-methylpyrimidin-4(3H)-one (5) showed weak anti-fungal activity against Candida albicans.

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Note | Regular issue | Vol 68, No. 2, 2006, pp.357-368
Published online: 27th December, 2005
DOI: 10.3987/COM-05-10618
A Facile Synthetic Route to Highly Functionalized 2,4-Pyrrolidinediones: A New Base-catalyzed Cyclization

Yu-Zi Jin, Bing Zhu Yin,* and Youn-Sik Lee*

*Division of environmental and Chemical Engineering, Nanomaterials Research Center, Chonbuk National University, Chonju 561-576, Korea

Abstract

2,4-Pyrrolidinedione derivatives were synthesized in 67-85% yield in one-pot reaction via base-catalyzed cyclization of α-(arylvinylcarbonyl)-α’-(N-arylaminocarbonyl)ketene dithioacetals formed in situ by the reaction of α-acetyl-α’-(N-arylaminocarbonyl)ketene dithioacetals with pyridinecarboxlaldehydes or benzaldehydes containing electron-withdrawing substituents.

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Note | Regular issue | Vol 68, No. 2, 2006, pp.369-374
Published online: 13th December, 2005
DOI: 10.3987/COM-05-10625
One-Pot Synthesis of 1-(2-, 3- or 4-Aminophenyl)- and 1-(4-Aminobenzyl)-3,4-dihydroisoqunolines

Iliyan Ivanov,* Stoyanka Nikolova, and Stela Statkova-Abeghe

*Department of Organic Chemistry, University of Plovdiv, 24, Tsar Assen Str. 4000 Plovdiv, Bulgaria

Abstract

1-Substituted 3,4-dihydro- and 1,2,3,4-tetrahydroisoquinoline derivatives were obtained in high yields from reactions of 2-(3,4-dimethoxyphenyl)ethylamine with aminobenzoic and aminophenylacetic acids in polyphosphoric acid.

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Note | Regular issue | Vol 68, No. 2, 2006, pp.375-380
Published online: 13th January, 2006
DOI: 10.3987/COM-05-10628
Microwave-assisted Gewald Synthesis of 2-Aminothiophenes Using Functional Ionic Liquid as Soluble Support

Yi Hu,* Ping Wei, He Huang, Shi-Qing Han, and Ping-Kai Ouyang*

*College of Life Science and Pharmaceutical Engineering, Nanjing University of Technology, Nanjing 210009, China

Abstract

A microwave-assisted liquid-phase Gewald synthesis of 2-aminothiophenes was developed using task-specific ionic liquid—[2-hydemim][BF4] as soluble support. This new synthetic method is simple and efficient, and the products are obtained in good to excellent yields with high purities, without the need for chromatographic purification.

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Note | Regular issue | Vol 68, No. 2, 2006, pp.381-386
Published online: 13th January, 2006
DOI: 10.3987/COM-05-10637
Acylated Cyanidin 3,7,3’-Trigllucosides with p-Hydroxybenzoic Acid from the Flowers of Dendrobium

Fumi Tatsuzawa,* Norio Saito, Tomohisa Yukawa, Koichi Shinoda, Atsushi Shigihara, and Toshio Honda

*Department of AGro-Enviromental Sciences, Hokkaido Junior College, Takushoku University, Fukagawa, Hokkaido 074-8585, Japan

Abstract

Two new acylated anthocyanins were isolated from the purple flowers of Dendrobium x superbiens, along with four known pigments. These pigments were all based on cyanidin 3,7,3’-triglucoside, and acylated variously with malonic, sinapic, and p-hydroxybenzoic acids. One of new anthocyanins was fully determined to be cyanidin 3-O-[6-O-(malonyl)-β-D-glucopyranoside]- 7-O-[6-O-(p-hydroxybenzoyl)-β-D-glucopyranoside]-3’-O-[6-O-(4-(β-D-glucopyranosyl)-p-hydroxybenzoyl)-β-D-glucopyranoside] by chemical and spectral methods. Another new pigment was provisionally determined to be cyanidin 3-malonylglucoside-7-glucosyl-p-hydroxybenzoylglucoside-3’-p-hydroxybenzoylglucoside.

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Note | Regular issue | Vol 68, No. 2, 2006, pp.387-393
Published online: 17th January, 2006
DOI: 10.3987/COM-05-10645
A Synthesis of N-Formylenamides of Isoquinoline

Iliyan Ivanov,* Stoyanka Nikolova, Stela Statkova-Abeghe, and Plamen Angelov

*Department of Organic Chemistry, University of Plovdiv, 24, Tsar Assen Str. 4000 Plovdiv, Bulgaria

Abstract

N-Formylenamides of isoquinoline (6) were obtained from N-[2-(2-acyl-4,5-dimethoxyphenyl)ethyl]formamides (5) by cyclization in the presence of catalytic amount of p-toluensulfonic acid. The starting keto formamides (5) were obtained by acylation of a N-[2-(3,4-dimethoxyphenyl)ethyl]formamides (1) with carboxylic acids or their anhydrides in polyphosphoric acid (PPA).

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Note | Regular issue | Vol 68, No. 2, 2006, pp.395-400
Published online: 17th January, 2006
DOI: 10.3987/COM-05-10656
Certain Cinnamonitriles React with 2-Methoxyfuran to Produce a New Phenylcyclopane Product

Kuniaki Itoh,* Shin Iwata, and Shigehisa Kishimoto

*Department of Chemistry, Faculty of Science, Kobe University, Nada-Ku, Kobe 6557-8501, Japan

Abstract

2-Methoxyfuran as a diene fails to generate a Diels-Alder adduct when it reacts with β-cyanostyrenes (cinnamonitriles). However, in the reaction with β-cyanostyrenes possessing additional electron-withdrawing groups (CN, CO2Et, SO2Ph and COPh), it yielded two new phenylcyclopropanes. The formation of the cyclopropane ring may occur through the opening of the furan ring in the β-cyanostyrene-furan complex (zwitterion) formed. The product formation process involves a sterically controlled intramolecular reaction.

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18 data found. 1 - 18 listed