반응 #81137

ord-254f6086c3394b339279d48bb5399aae

반응 조건

온도
-70°CELSIUS
상세 조건
See reaction.notes.procedure_details.

후처리

  1. 1
    workup.STIRRINGThe mixture was stirred at the same temperature for 1 hour
  2. 2
    workup.ADDITIONwas dropwise added
  3. 3
    workup.STIRRINGwith stirring
  4. 4
    온도under cooling to -20° C
  5. 5
    workup.STIRRINGThe mixture was stirred at room temperature for 1 hour
  6. 6
    기타the organic layer was collected by separation
  7. 7
    세척washed with a saturated sodium chloride aqueous solution
  8. 8
    건조dried over anhydrous magnesium sulfate
  9. 9
    기타The drying agent was separated by filtration
  10. 10
    workup.DISTILLATIONthe solvent was distilled off under reduced pressure

실험 절차

10.5 g of tert-butyl 2-(3,4-dichlorobenzyl)acetoacetate (which was prepared by treating 3,4-dichlorobenzyl chloride and tert-butyl acetoacetate with potassium tert-butoxide in tert-butanol) was dissolved in 100 ml of tetrahydrofuran, and 45 ml of a 1M tetrahydrofuran solution of lithium tri-sec-butylborohydride was added thereto with stirring under cooling to -70° C. The mixture was stirred at the same temperature for 1 hour. Then, 20 ml of water and 15 ml of a 3N sodium hydroxide aqueous solution were added to the reaction solution, and 15 ml of a 30% hydrogen peroxide aqueous solution was dropwise added thereto with stirring under cooling to -20° C. The mixture was stirred at room temperature for 1 hour. Then, hexane was added to the reaction solution, and the organic layer was collected by separation, then washed with a saturated sodium chloride aqueous solution and dried over anhydrous magnesium sulfate. The drying agent was separated by filtration, and then the solvent was distilled off under reduced pressure. The residue was subjected to silica gel column chromatography (hexane/ethyl acetate=10/1→5/1) to obtain 3.79 g (yield: 33%) of tert-butyl (2RS, 3RS)-2-(3,4-dichlorobenzyl)-3-hydroxybutanoate.

출처

DOI: 10.6084/m9.figshare.5104873.v1특허: US05616803uspto-grants-1997_04