反应详情

To 1.0 L of a solution of 20.0 g of dimethyl 2-cyano-3-phenylpentanedioate and 36.4 g of cobalt chloride (TI) hexahydrate in methanol was added carefully 17.4 g of sodium borohydride under ice-cooling. After stirring at room temperature for 30 minutes, 1 M hydrochloric acid (1.0 L) was added thereto, followed by further stirring at room temperature for 30 minutes. The reaction mixture was concentrated under reduced pressure to a half amount thereof, and then extracted with ethyl acetate. The organic layer was washed with saturated brine, and dried over anhydrous sodium sulfate. After filtration, the filtrate was concentrated under reduced pressure, and the residue was purified by silica gel column chromatography (chloroform-methanol) to obtain 3.84 g of methyl rel-(3R,4S)-6-oxo-4-phenylpiperidine-3-carboxylate as a white solid.

1. temperaturecooling
2. stirringby further stirring at room temperature for 30 minutes
3. concentrationThe reaction mixture was concentrated under reduced pressure to a half amount
4. extractionextracted with ethyl acetate
5. washThe organic layer was washed with saturated brine
6. dry with materialdried over anhydrous sodium sulfate
7. filtrationAfter filtration
8. concentrationthe filtrate was concentrated under reduced pressure
9. customthe residue was purified by silica gel column chromatography (chloroform-methanol)