Sodium borohydride → tert-butyl (2S,3S)-1-(tert-butyldimethylsilyloxy)-4-hydroxy-3-(4-(trifluoromethyl)phenyl)butan-2-ylcarbamate

HRID 661092Notes

Reaction equation

HRID 661092 reaction equation
[Si:1]([O:8][CH2:9][C@@H:10]([NH:25][C:26](=[O:32])[O:27][C:28]([CH3:31])([CH3:30])[CH3:29])[C@H:11]([C:15]1[CH:20]=[CH:19][C:18]([C:21]([F:24])([F:23])[F:22])=[CH:17][CH:16]=1)/[CH:12]=C/C)([C:4]([CH3:7])([CH3:6])[CH3:5])([CH3:3])[CH3:2].[BH4-].[Na+].C[OH:36].C(Cl)Cl>>[Si:1]([O:8][CH2:9][C@@H:10]([NH:25][C:26](=[O:32])[O:27][C:28]([CH3:31])([CH3:29])[CH3:30])[C@H:11]([C:15]1[CH:20]=[CH:19][C:18]([C:21]([F:23])([F:24])[F:22])=[CH:17][CH:16]=1)[CH2:12][OH:36])([C:4]([CH3:6])([CH3:7])[CH3:5])([CH3:3])[CH3:2]

Participants

4

Reactant 3

HCID 4311764Sodium borohydrideHCID 21226129Dichloromethane methanolHCID 86613773tert-butyl (2S,3S,E)-1-(tert-butyldimethylsilyloxy)-3-(4-(trifluoromethyl)phenyl)hex-4-en-2-ylcarbamate

Product 1

HCID 57634005tert-butyl (2S,3S)-1-(tert-butyldimethylsilyloxy)-4-hydroxy-3-(4-(trifluoromethyl)phenyl)butan-2-ylcarbamateYield 97%

Conditions

Temperature
-78 °C

Procedure

Tert-butyl (2S,3S,E)-1-(tert-butyldimethylsilyloxy)-3-(4-(trifluoromethyl)phenyl)hex-4-en-2-ylcarbamate (2.0 g, 4.2 mmol) was dissolved in 40 mL of 1:1 MeOH/DCM, and the mixture was chilled to −78° C. Ozone was bubbled through the mixture until a blue color persisted. Nitrogen was then bubbled through the mixture for 15 minutes. NaBH4 (0.80 g, 21 mmol) was added, and the mixture was warmed to room temperature. After 3 hours, the mixture was quenched with aq NH4Cl. The mixture was extracted three times with 50 mL of DCM. The combined organic extracts were dried over MgSO4. Filtration and concentration under reduced pressure afforded tert-butyl (2S,3S)-1-(tert-butyldimethylsilyloxy)-4-hydroxy-3-(4-(trifluoromethyl)phenyl)butan-2-ylcarbamate (1.9 g, 97% yield) as a white solid. 1H NMR (400 MHz, CDCl3) δ ppm 7.56 (d, J=8.03 Hz, 2H) 7.32 (d, J=8.03 Hz, 2H) 4.51 (s, 1H) 4.22-4.16 (m, 1H) 3.90-3.66 (m, 3H) 3.47 (d, J=5.52 Hz, 2H) 3.15-3.20 (m, 1H) 1.45 (s, 9H) 0.84 (s, 9H) 0.01 (s, 3H)-0.01 (s, 3H).

Workup

  1. customOzone was bubbled through the mixture until a blue color
  2. customNitrogen was then bubbled through the mixture for 15 minutes
  3. temperaturethe mixture was warmed to room temperature
  4. customthe mixture was quenched with aq NH4Cl
  5. extractionThe mixture was extracted three times with 50 mL of DCM
  6. dry with materialThe combined organic extracts were dried over MgSO4
  7. filtrationFiltration and concentration under reduced pressure

Sources & evidence

ORD record
ord-531fb8ce861142b59e3972e866d62440
Source dataset
uspto-grants-2011_12
Patent number
US08084479B2

Reaction notes

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