Keiko Sekiguchi

Research Field

ChemInform Abstract: Cycloadditions in Syntheses. Part 51. Use of 1,3‐Dioxin‐4‐ones and Their Related Compounds in Synthesis. Part 28. Asymmetric de Mayo Reactions Using Chiral Spirocyclic Dioxinones.

ChemInform (1991)

Masayuki Sato Y. Abe Kazuhisa Takayama Keiko Sekiguchi Chikara Kaneko

Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

10.1002/chin.199132218

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A SHORT SYNTHESIS OFcis-2-FORMYL-5-HYDROXY-2-CYCLOPENTENE-1-ACETIC ACID γ-LACTONE. THE KEY INTERMEDIATE OF PROSTAGLANDIN SYNTHESIS

Chemistry Letters (1985)

Masayuki Sato Keiko Sekiguchi Chikara Kaneko

Abstract A practically one-pot synthesis of the title compound from 2,2-dimethyl-1,3-dioxin-4-one and cis-2-cyclopentene-1,4-diol by an application of de Mayo method is described.

Cyclopentene

10.1246/cl.1985.1057

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Citations (7)

Synthesis of Optically Active Cyclopenta[c]pyran-4-carboxylic Acid Derivatives, Building Blocks for Iridoids. An Attractive Alternative to Asymmetric de Mayo Reaction

Chemistry Letters (1989)

Masayuki Sato Kazuhisa Takayama Keiko Sekiguchi Yoshito Abe Toshio Furuya

Abstract A new asymmetric de Mayo reaction leading to enantiomerically pure iridoids has been elaborated using chiral spirocyclic dioxinone as the photochemical equivalent of diformylacetate.

Pyran

10.1246/cl.1989.1925

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Citations (4)

ChemInform Abstract: CYCLOADDITIONS IN SYNTHESES. XXI. SYNTHESIS OF 1,3-DIOXIN-4-ONES UNSUBSTITUTED AT THE 5- AND 6-POSITIONS AND THEIR PHOTOADDITION TO ALKENES

Chemischer Informationsdienst (1985)

Masayuki Sato Hiromichi Ogasawara Keiko Sekiguchi Chikara Kaneko

Abstract S‐Formylmeldrum‐ Säure (I) liefert bei der Thermolyse in Gegenwart von Dialkylketonen (II) die Dialkyldioxinone (III).

10.1002/chin.198513195

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Synthesis of 1,3-Dioxin-4-ones Unsubstituted at the 5- and 6-Positions and Their Photoaddition to Alkenes

Heterocycles (1984)

Chikara Kaneko Masayuki Sato Hiromichi Ogasawara Keiko Sekiguchi Chikara Kaneko

A b s t r a c t -A general synthetic method of 5.6-unsubstituted 1,3-dioxin-4-ones and their photoadditlon to alkenes are described.The photoadducts thus obtained were found to give, merely by refluxing in water, alkanes having carboxaldehyde and acetic acid appendages at the vlcinal position.Two of the present authors (M. S. and H. 0.) recently reportedZ the synthesis of

10.3987/r-1984-11-2563

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Citations (18)

ChemInform Abstract: A Short Synthesis of cis‐2‐Formyl‐S‐hydroxy‐2‐cyclopentene‐1‐acetic Acid 7‐Lactone.

Chemischer Informationsdienst (1986)

Masayuki Sato Keiko Sekiguchi Chikara Kaneko

Abstract Das Lacton (III), ein Vorprodukt bei Prostaglandinsynthesen, wird wie angegeben neben der leicht abtrennbaren Verbindung (IV) erhalten.

Cyclopentene

10.1002/chin.198603173

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ChemInform Abstract: Synthesis of Optically Active Cyclopenta(c)pyran‐4‐carboxylic Acid Derivatives, Building Blocks for Iridoids. An Attractive Alternative to Asymmetric de Mayo Reaction.

ChemInform (1990)

Masayuki Sato Kazuhisa Takayama Keiko Sekiguchi Y. Abe Takeshi Furuya

Abstract The formylacetate (I) reacts with the dimethylformamide acetal (II) to give the dimethylaminomethylene compound (III) which is hydrolyzed, yielding the hydroxymethylene analogue (IV).

Pyran

10.1002/chin.199025166

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ChemInform Abstract: SYNTHETIC STUDIES OF NAPHTHOQUINONE DERIVATIVES. 3. REACTIONS OF 5‐SUBSTITUTED 2,3‐DICHLORO‐ AND 2,3,6,8‐TETRACHLORO‐1,4‐NAPHTHOQUINONES WITH ANILINES

Chemischer Informationsdienst (1981)

T. KASAI T. NAKAMORI Keiko Sekiguchi

Abstract Die Umsetzung der Dichlornaphthochjnone (I) mit den Anilinen (II) zu den Anilinonaphthochinonen (III) wird bezüglich der Isomerenverteilung untersucht.

1,4-Naphthoquinone

Naphthoquinone

10.1002/chin.198117196

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Use of 1,3‐dioxin‐4‐ones and their related compounds in synthesis. Part 28. Asymmetric de mayo reactions using chiral spirocyclic dioxinones

Journal of Heterocyclic Chemistry (1991)

Masayuki Sato Yoshito Abe Kazuhisa Takayama Keiko Sekiguchi Chikara Kaneko

Abstract The use of rigid spirocyclic dioxinones having 1‐menthone as the chiral auxiliary as the enones in the photo[2 + 2]cycloaddition reactions opened novel methods for obtaining enantiomerically pure compounds, such as iridoids. Convex side preference of the sofa‐conformation of these dioxinones in the photoaddition to cyclopentene increases up to 100% by introducing either a bulky substituent or 5‐hexenyl group at the 3‐position to these dioxinones and, hence, highly asymmetric inter‐ and intramolecular de Mayo reactions have been disclosed.

Cyclopentene

Asymmetric induction

10.1002/jhet.5570280207

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Citations (23)

ChemInform Abstract: SYNTHESIS OF 5,6‐UNSUBSTITUTED 1,3‐DIOXIN‐4‐ONES

Chemischer Informationsdienst (1985)

Masayuki Sato Keiko Sekiguchi Hiromichi Ogasawara Chikara Kaneko

Abstract Aus Formyl‐meldrumsäure (I) und den Carbonylverbindungen (II) werden in siedendem Toluol die Dioxinone (III) erhalten.

10.1002/chin.198528232

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Citations (4)