반응 #440432

반응 방정식

AD-mix-β

4-Methylene-6-chloro-8-difluoromethoxychromane

tert-butanol

tert-butanol

Sodium sulfite

→

sub-title compound

수율 88.0%

(R)-4-Hydroxy-4-hydroxymethyl-6-chloro-8-difluoromethoxychromane

수율 88.0%

용매

water

water

반응 조건

후처리

1. 1
   온도to warm to room temperature
2. 2
   workup.STIRRINGstirred for 1 h
3. 3
   기타The layers were separated
4. 4
   추출the aqueous phase was extracted with EtOAc (2×)
5. 5
   건조The combined ethyl acetate phases were dried (Na2SO4)
6. 6
   기타evaporated
7. 7
   기타The crude product was chromatographed on silica gel
8. 8
   세척eluting with methylene chloride:ethyl acetate (4:6)

실험 절차

To a mixture of tert-butanol (46 mL) and water (46 mL) was added AD-mix-β (18.6 g). The mixture was cooled to 0° C. 4-Methylene-6-chloro-8-difluoromethoxychromane (3.2 g 12.97 mmol, see step (vi) above) in tert-butanol (11 mL) and water (11 mL) was added. The mixture was stirred at 0° C. for 24 h. Sodium sulfite (19.0 g, 150.74 mmol) was added, and the mixture was allowed to warm to room temperature and stirred for 1 h. The layers were separated and the aqueous phase was extracted with EtOAc (2×). The combined ethyl acetate phases were dried (Na2SO4) and evaporated. The crude product was chromatographed on silica gel, eluting with methylene chloride:ethyl acetate (4:6), to afford 3.2 g (88%) of the sub-title compound.

출처