| 摘要 |
Hexamethylphosphoramide (HMPA) was added to a reaction vessel containing (R)-1,1′-binaphthyl-2,2′-dithiol and potassium hydroxide. The vessel was purged with oxygen and stirred at 80° C. for 5 days under 7 atmospheres of oxygen. After being cooled to room temperature, the reaction product was purified to yield potassium (R)-1,1′-binaphthyl-2,2′-disulfonate. The (R)-1,1′-binaphthyl-2,2′-disulfonic acid obtained from the disulfonate and 2,6-diphenylpyridine were stirred in acetonitrile, and then the solvent was evaporated under reduced pressure. Subsequently, magnesium sulfate and distilled CH2Cl2 were added to the reaction product, and the mixture was stirred at room temperature for 30 minutes. The resulting solution was cooled to 0° C. Benzaldehyde imine whose nitrogen is protected with Cbz and subsequently acetyl acetone were dropped into the solution over a period of 1 hour. The resulting mixture was further stirred at 0° C. for 30 minutes. A correspondingβ-aminocarbonyl derivative was thus produced with an yield of 91% and an enantiomeric excess of 90% ee.
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