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Asymmetric epoxidation catalyzed by novel azacrown ether-type chiral quaternary ammonium salts under phase-transfer catalytic conditions

7 ASYMMETRIC EPOXIDATION CATALYZED BY NOVEL AZACROWN ETHER-TYPE CHIRAL QUATERNARY AMMONIUM SALTS UNDER PHASE-TRANSFER CATALYTIC CONDITIONS [Pg.228]

Kazushige Hori, Keita Tani and Yasuo Tohda [Pg.228]

Division of Natural Science, Osaka Kyoiku University, 4-698-1 Asahigaoka, Kashiwara, Osaka 582-8582, Japan [Pg.228]

5)-Oxybis[2-(ethyleneoxy)-2 -hydroxy-1,1 -binaphthyl] (2.32 g, 3.61 mmol) and potassium carbonate (l.lOg, 7.96mmol) were placed in a 300mL round-bottomed flask equipped with a reflux condenser and a magnetic stirrer bar. Dry methyl ethyl ketone (142 mL) was then added and the mixture was refluxed on an oil bath for 1 h. To this solution, Af,Af-bis-(2-p-nitrobenzenesulfonyloxyethyl)-A -p-nitrobenzenesulfonamide dichloromethane complex (3.44g, 4.32 mmol) was added. [Pg.230]

After the resulting mixture was heated under reflux for 24 h, the solvent was evaporated under reduced pressure. To the residue was added water (50 mL) and the mixture was extracted with dichloromethane (3 x 25 mL) using a separatory funnel. The combined organic extracts were washed with brine (25 mL), dried over anhydrous magnesium sulfate, and concentrated in vacuo to afford the crude product. [Pg.230]


Hori, K., Tamura, M., Tani, K., Nishiwaki, N., Ariga, M. and Tohda, Y. Asymmetric Epoxidation Catalyzed by Novel Azacrown Ether-type Chiral Quaternary Ammonium Salts under Phase-transfer Catalytic Conditions. Tetrahedron Lett. 2006, 47, 3115-3118. [Pg.33]




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Ammonium chiral

Ammonium salts, chiral

Asymmetric catalytic

Asymmetric chirality

Asymmetric epoxidation

Asymmetric epoxidation chiral quaternary ammonium salts

Asymmetric epoxidation conditions

Asymmetric epoxidation under phase-transfer catalytic

Asymmetric phase-transfer

Asymmetric transfer

Azacrown ether

Azacrown ether-type quaternary ammonium

Azacrowns

Catalytic asymmetric epoxidation

Catalytic asymmetric phase-transfer

Catalytic conditions

Catalytic phase

Chiral catalytic phase transfer

Chiral epoxidations

Chiral epoxide

Chiral epoxides

Chiral ether

Chiral phases

Chirality types

Chirality, transfer

Chirality/Chiral phases

Epoxidation catalytic

Epoxidation chiral

Epoxidations, asymmetric

Epoxidations, catalytic

Epoxidations, catalytic asymmetric

Epoxide conditions

Epoxides asymmetric epoxidation

Epoxides asymmetric phase-transfer

Epoxides catalyzed

Epoxides conditions

Ether salts

Phase epoxidation

Phase, types

Phases chirality

Quaternary ammonium salts

Quaternary salts

Salt conditions

Salt, ethereal

Salts chiral

Salts transfer

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