著者

大石 武 秋田 弘幸

出版者

The Society of Synthetic Organic Chemistry, Japan

雑誌

有機合成化学協会誌 (ISSN:00379980)

巻号頁・発行日

vol.41, no.11, pp.1031-1043, 1983-11-01 (Released:2010-01-22)

参考文献数

34

被引用文献数

13 15

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Asymmetric reduction of α-methyl β-keto ester and β-methyl α-keto ester by means of yeasts was carried out. Both keto esters were found to be reduced by a variety of yeasts to give optically active hydroxy esters having two chiral centers. The absolute configuration and the optical purity of the reduction products were primarily determined by measuring the 400 MHz NMR spectra of the (+) -MTPA esters of the alcohols produced.The successful use of the chiral synthons prepared by the present method in high optical purity to the synthesis of (-) -oudemansin is described.

著者

梅澤 勲 野澤 雅子 南雲 紳史 秋田 弘幸

出版者

公益社団法人日本薬学会

雑誌

Chemical & pharmaceutical bulletin (ISSN:00092363)

巻号頁・発行日

vol.43, no.7, pp.1111-1118, 1995-07-15

被引用文献数

1

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Three kinds of oudemansin X, (-)-1,(+)-1 and (±)-1,were totally synthesized. The key point in the present chiral synthesis was the enantioselective acetylation of the racemic alcohols, (±)-5 and (±)-8,using lipase in an organic solvent. The synthetic (-)-1 was found to exhibit strong antifungal activity against several molds and yeasts.

著者

/ 船越 和久 末宗 洋 大石 武 秋田 弘幸 酒井 浄 Kiyoshi Sakai

出版者

The Pharmaceutical Society of Japan

雑誌

Chemical and Pharmaceutical Bulletin (ISSN:00092363)

巻号頁・発行日

vol.34, no.7, pp.3058-3060, 1986-07-25 (Released:2008-03-31)

参考文献数

9

被引用文献数

7 9

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Microbial reduction of 7-methoxycarbonyl bicyclo[4. 3. 0]non-3-en-8-one ((±)-3) afforded the optically active (-)-3, which was efficiently converted by ring contraction using thallium (III) nitrate to the intermediate (11) used to synthesize carbacyclin (1).

著者

末宗 洋 林 教行 舟越 和久 秋田 弘幸 大石 武 酒井 浄

出版者

The Pharmaceutical Society of Japan

雑誌

Chemical and Pharmaceutical Bulletin (ISSN:00092363)

巻号頁・発行日

vol.33, no.5, pp.2168-2170, 1985-05-25 (Released:2008-03-31)

参考文献数

12

被引用文献数

24 29

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(S)-13-Hydroxy-9Z, 11E-octadecadienoic acid, a defensive substance in rice, was synthesized with high enantioselectivity by the reduction of the corresponding ketone with yeasts.

著者

秋田 弘幸 古市 昭也 越地 弘子 堀越 弘毅 大石 武

出版者

The Pharmaceutical Society of Japan

雑誌

Chemical and Pharmaceutical Bulletin (ISSN:00092363)

巻号頁・発行日

vol.32, no.4, pp.1342-1348, 1984-04-25 (Released:2008-03-31)

参考文献数

12

被引用文献数

6 8

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The synthesis of optically active α-hydroxy β-methyl esters V by means of microbiological reduction of the corresponding α-keto β-methyl esters IV was carried out. Methyl 3-phenyl-2-oxobutyrate 3 was found to be reduced by a variety of yeasts to the α-hydroxy β-methyl esters (7b and 8a) with (2R, 3S)-and (2R, 3R)-configurations, respectively, and by carrying out screening experiments, yeasts which give products with high optical purity were actually found.

著者

秋田 弘幸 古市 昭也 越地 弘子 堀越 弘毅 大石 武

出版者

The Pharmaceutical Society of Japan

雑誌

Chemical and Pharmaceutical Bulletin (ISSN:00092363)

巻号頁・発行日

vol.32, no.4, pp.1333-1341, 1984-04-25 (Released:2008-03-31)

参考文献数

13

被引用文献数

14 17

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Microbiological asymmetric reduction of methyl 3-(2-furyl)-2-methyl-3-oxopropionate (5) by various yeasts was carried out. Four kinds of methyl 3-(2-furyl)-3-hydroxy-2-methyl propionates (6a-6d) could be obtained separately from the prochiral β-keto ester 5 by reduction with properly selected microorganisms. In particular, the desired syn-isomer 6a was obtained with high optical purity (>99% e.e.). Both the chemical yield and the optical purity of the reduction products (6a-6d) were significantly improved when fermentation was carried out on a large scale using a 30 1 jar fermentor or a 200 1 tank.

著者

秋田 弘幸 古市 昭也 越地 弘子 堀越 弘毅 大石 武

出版者

The Pharmaceutical Society of Japan

雑誌

Chemical and Pharmaceutical Bulletin (ISSN:00092363)

巻号頁・発行日

vol.31, no.12, pp.4384-4390, 1983-12-25 (Released:2008-03-31)

参考文献数

13

被引用文献数

10 13

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In order to synthesize four optically active methyl 2-methylmalates (10-13), microbiological asymmetric reduction of the corresponding dimethyl 2-methyl-3-oxosuccinate (9) was carried out. The β-keto diester 9 was found to be reduced by fermenting baker's yeast (Saccharomyces cerevisiae) and Candida albicans to afford a mixture of the (2R, 3R)-isomer 10 and the (2S, 3R)-isomer 11. Although the optical purity of 10 produced by Candida albicans was reasonably high (95% e.e.), optical yields of other products were unexpectedly low. However, identification of the four possible isomers 14-17 was found to be easily carried out by means of nuclear magnetic resonance spectroscopy.

著者

秋田 弘幸 古市 昭也 越地 弘子 堀越 弘毅 大石 武

出版者

The Pharmaceutical Society of Japan

雑誌

Chemical and Pharmaceutical Bulletin (ISSN:00092363)

巻号頁・発行日

vol.31, no.12, pp.4376-4383, 1983-12-25 (Released:2008-03-31)

参考文献数

19

被引用文献数

18 30

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The synthesis of optically active α-methyl β-hydroxy esters I by means of microbiological reduction of the corresponding β-keto esters II was carried out. Benzyl 2-methyl-3-oxobutyrate 1 was found to be reduced by a variety of yeasts to the α-methyl β-hydroxy esters with (2R, 3S)- and (2S, 3S)-configurations (2 and 3, respectively), and by carrying out screening experiments, yeasts which give each product with high optical purity were isolated. Moreover, the absolute configuration and the optical purity of the reduction products were found to be determinable from the 400 MHz nuclear magnetic resonance spectra of the (+)-α-methyoxy-α-trifluoromethylphenylacetyl esters of the alcohols produced.

著者

梅澤 勲 野澤 雅子 南雲 紳史 秋田 弘幸

出版者

公益社団法人 日本薬学会

雑誌

CHEMICAL & PHARMACEUTICAL BULLETIN (ISSN:00092363)

巻号頁・発行日

vol.43, no.7, pp.1111-1118, 1995

被引用文献数

5

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Three kinds of oudemansin X, (-)-1, (+)-1 and (±)-1, were totally synthesized. The key point in the present chiral synthesis was the enantioselective acetylation of the racemic alcohols, (±)-5 and (±)-8, using lipase in an organic solvent. The synthetic (-)-1 was found to exhibit strong antifungal activity against several molds and yeasts.

著者

岡野 耕二 水原 由加子 末宗 洋 秋田 弘幸 酒井 浄

出版者

The Pharmaceutical Society of Japan

雑誌

Chemical and Pharmaceutical Bulletin (ISSN:00092363)

巻号頁・発行日

vol.36, no.4, pp.1358-1365, 1988-04-25 (Released:2008-03-31)

参考文献数

9

被引用文献数

5 10

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During a detailed examination on the cyclization of 1, 4-diketones to cyclopentenones, we have found that two oxygenated products (4 and 5) are formed when the purification by column chromatography on silica gel takes a long time. The highly functionalized cyclopentenone (4a) obtained as the major product in this manner seems to be an attractive synthon for the synthesis of natural products. For eaxmple, the chiral synthon (1S, 4S)-4-benzyloxycarbonyl-1, 4-dihydroxy-2-methoxycarbonyl-3-methyl-2-cyclopentene ((+)-7) with high optical purity was obtained by microbial reduction with Rhodotorula rubra CCY 20-7-1, and the absolute stereochemistry was established independently by using the exciton chirality method and the chemical method.

著者

末宗 洋 水原 由加子 秋田 弘幸 酒井 浄

出版者

The Pharmaceutical Society of Japan

雑誌

Chemical and Pharmaceutical Bulletin (ISSN:00092363)

巻号頁・発行日

vol.34, no.8, pp.3440-3444, 1986-08-25 (Released:2008-03-31)

参考文献数

12

被引用文献数

24 44

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An enzymatic synthesis of 2, 3-O-isopropylidene-sn-glycerol (10), the synthetic key intermediate for platelet-activating factor, was achieved. Several 1, 3-di-O-acyl-2-benzylglycerols (5a-d) were synthesized from dihydroxyacetone dimer (2), and subjected to enzyme-catalyzed asymmetric hydrolysis. The optical purities of the mono-hydrolyzed products (6) were determined from the 400 MHz proton nuclear magnetic resonance spectra after conversion of 6 to the esters of (-)α-methoxy-α-trifluoromethylphenylacetic acid. Upon hydrogenolysis of the benzyl ether, followed by protection of diol and hydrolysis of the acetate, (-)-6a afforded 10.

著者

秋田 弘幸

出版者

九州大学

巻号頁・発行日

1975

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