Special Issue

Albert Eschenmoser's Special Issues, Vol. 82, No. 1, 2010

69 data found. 61 - 69 listedFirst Previous
Note | Special issue | Vol 82, No. 1, 2010, pp. 839 - 842
Published online: 10th May, 2010
DOI: 10.3987/COM-10-S(E)18
Dehydrofuligoic Acid, a New Yellow Pigment Isolated from the Myxomycete Fuligo septica f. flava

Akinori Shintani, Kazufumi Toume, Yukinori Yamamoto, and Masami Ishibashi*

*Department of Natural Products Chemistry, Graduate School of Pharmaceutical Science, Chiba University, 1-33 Yayoi-cho, Inage-ku, Chiba 263-8522, Japan

Abstract

Dehydrofuligoic acid (1), a new yellow pigment with a chlorinated polyene-pyrone acid structure, was isolated from field-collected fruit bodies of the myxomycete Fuligo septica f. flava, and its structure was elucidated from spectral data.

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Note | Special issue | Vol 82, No. 1, 2010, pp. 843 - 850
Published online: 16th June, 2010
DOI: 10.3987/COM-10-S(E)32
Efficient Transformation of Flav-3-enes Using Reductive Elimination of Flav-4-triflate

Yoshihito Kohari, Yukio Hoshino, Haruo Matsuyama, and Hiroto Nakano*

*Biological function Research Unit, College of Environmental Technology, Muroran Institute of Technology, 27-1 Mizumoto, Muroran, Hokkaido 050-8585, Japan

Abstract

Flav-3-enes were prepared in excellent yields (up to 98%) by reductive elimination of flav-3-ene-4-triflates in the presence of palladium acetate, formic acid and tri-n-buthylamine.

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Note | Special issue | Vol 82, No. 1, 2010, pp. 851 - 855
Published online: 1st July, 2010
DOI: 10.3987/COM-10-S(E)38
Synthesis of Graphislactone H

Hitoshi Abe,* Tomoko Fukumoto, Yoshikazu Horino, Takashi Harayama, and Yasuo Takeuchi*

*Department of Applied Chemistry, Faculty of Engineering, Toyama University, Gofuku 3190, Toyama 930-8555, Japan

Abstract

Short step synthesis of graphislactone H was achieved through a palladium-mediated aryl-aryl coupling reaction.

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Note | Special issue | Vol 82, No. 1, 2010, pp. 857 - 865
Published online: 7th July, 2010
DOI: 10.3987/COM-10-S(E)45
Simple Three Steps Synthesis of Potential Medicine for Metabolic Syndrome

Kazuhiro Adachi, Kyosuke Michigami, and Masahiko Hayashi*

*Department of Chemistry , Graduate School of Science, Kobe University, 1-1 Rokkodai-cho, Nada-ku, Kobe 657-8501, Japan

Abstract

Efficient synthesis of the derivatives of JTP-426467 was achieved by three steps including 1) oxidative aromatization promoted by activated carbon, 2) hydrogenation, 3) amidation to afford the desired amide compounds in high yield.

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Note | Special issue | Vol 82, No. 1, 2010, pp. 867 - 880
Published online: 7th July, 2010
DOI: 10.3987/COM-10-S(E)47
A Convenient Approach to the Synthesis of Furo- and Thieno-[3,2-c]pyridine Derivatives

Hiroshi Maruoka,* Fumi Okabe, Keishi Yamasaki, Eiichi Masumoto, Toshihiro Fujioka, and Kenji Yamagata

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

Abstract

The title compounds were prepared from 4,5-dihydro-3-furan- and -3-thiophene-carbonitriles having an active methylene group at C-2 position 1, 2, 7, and 8 as key starting materials. Compounds 1 and 2 condensed with N,N-dimethylformamide dimethyl acetal to give the corresponding enamines 3 and 4. This condensation was followed by exchange reaction of amines and subsequent intramolecular cyclization reaction in the presence of ammonium acetate to lead the corresponding furo- and thieno-[3,2-c]pyridines 5 and 6. On the other hand, the reactions of compounds 7 and 8 with amines such as aqueous ammonium hydroxide and benzylamine afforded the intermediate acetamide derivatives A, without isolation of them, which underwent intramolecular cyclization reaction in the presence of sodium methoxide to yield the corresponding furo- and thieno-[3,2-c]pyridin-6(2H)-ones 912.

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Note | Special issue | Vol 82, No. 1, 2010, pp. 881 - 886
Published online: 5th July, 2010
DOI: 10.3987/COM-10-S(E)48
Concise and Efficient Synthesis of 4-Hydroxy-2-pyrones from Pentane-2,4-diones

Masahiro Yoshida,* Hironobu Takai, Chika Mitsuhashi, and Kozo Shishido*

*Graduate School of Pharmaceutical Sciences, University of Tokushima, Sho-machi, Tokushima 770-8505, Japan

Abstract

A concise method for the synthesis of 4-hydroxy-2-pyrones has been developed. Various 5-substituted 4-hydroxy-2-pyrones were efficiently prepared in two steps from 3-substituted pentane-2,4-diones.

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Note | Special issue | Vol 82, No. 1, 2010, pp. 887 - 893
Published online: 29th July, 2010
DOI: 10.3987/COM-10-S(E)50
Convenient Synthesis of Optically Pure 8-Methoxy-2-methyl-1,2,3,4-tetrahydroquinoline and 2-Methyl-1,2,3,4-tetrahydroquinoline

Jie Tang, Guo-Fang Jiang,* and Yong-Gui Zhou*

*Dalian Institute of Chemical Physics, 457 Zhongshan Road, Dalian 116023, China

Abstract

A convenient method was developed to synthesize optically pure 8-methoxy-2-methyl-1,2,3,4-tetrahydroquinoline (2a) and 2-methyl-1,2,3,4-tetra-hydroquinoline (2b) by combining the methods of catalytic hydrogenation and classical resolution. The catalytic system ([Ru(p-cymene)Cl2]2/I2) showed high efficiency in preparing racemic 2a and 2b, which were successfully resolved using commercial tartaric acid derivatives, and both enantiomers were obtained in moderate yield with >99% ee.

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Note | Special issue | Vol 82, No. 1, 2010, pp. 895 - 907
Published online: 13th July, 2010
DOI: 10.3987/COM-10-S(E)56
[2+2+2]-Cocyclotrimerization of 6-Alkynyl-7-benzylpurines with α,ω-Diynes

Stanislav Opekar, Pavel Turek, Radek Pohl, Blanka Klepetářová, Ivan Votruba, Michal Hocek,* and Martin Kotora*

*Department of Organic and Nuclear Chemistry, Faculty of Science, Charles University, Hlavova 8, 128 43 Praha 2, Czech Republic

Abstract

6-Alkynyl-7-benzylpurines were prepared by the Sonogashira reaction from 6-chloro-7-benzylpurines and terminal alkynes. The prepared alkynylpurines were cyclotrimerized with various 1,6-diynes in the presence of Ni(cod)2/2PPh3 catalytic system into the corresponding 6-aryl-7-benzylpurines under ambient conditions. The prepared 6-alkynyl- and 6-aryl-7-benzylpurines were tested for cytostatic activity.

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Note | Special issue | Vol 82, No. 1, 2010, pp. 909 - 915
Published online: 22nd July, 2010
DOI: 10.3987/COM-10-S(E)57
Simple Deuterium Introduction at α-Position of Carbonyl in Diazirinyl Derivatives for Photoaffinity Labeling

Yuta Murai, Miho Takahashi, Yasuyuki Muto, Yasumaru Hatanaka, and Makoto Hashimoto*

*Graduate School of Agriculture, Hokkaido University, Kita 9 Nishi 9, Kita-ku, Sapporo, Hokkaido 060-0589, Japan

Abstract

Post-functional deuterium incorporation into diazirinyl acetophenone derivatives is reported. Treatment of the compounds with sodium hydroxide in CH3OD at rt for 10 min achieved deuterium incorporation at α-position of the carbonyl group without decomposition of diazirinyl ring. Further deuterium can introduce by reduction of benzyl carbonyl with triethylsilane-d-TFA. Straightforward deuterium introduction into diazirinyl derivatives may contribute to the functional analysis of low molecular compounds with diazirine-based photoaffinity labeling.

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