Acetic Acid → (2R,3S)-N-tert-Butyloxycarbonyl-3-(tert-butyldimethylsilanyloxy)-2-(1-hydroxyethyl)pyrrolidine

HRID 1864714Notes

Reaction equation

HRID 1864714 reaction equation
[C:1]([O:5][C:6]([N:8]1[CH2:12][CH2:11][C@H:10]([O:13][Si:14]([C:17]([CH3:20])([CH3:19])[CH3:18])([CH3:16])[CH3:15])[C@H:9]1[CH:21]=[O:22])=[O:7])([CH3:4])([CH3:3])[CH3:2].C[Mg+].[Br-].[CH3:26]C(O)=O>CCOC(C)=O>[C:1]([O:5][C:6]([N:8]1[CH2:12][CH2:11][C@H:10]([O:13][Si:14]([C:17]([CH3:20])([CH3:19])[CH3:18])([CH3:16])[CH3:15])[C@H:9]1[CH:21]([OH:22])[CH3:26])=[O:7])([CH3:4])([CH3:3])[CH3:2]

Participants

5

Reactant 3

HCID 176Acetic AcidHCID 16731848(2S,3S)-tert-Butyl 3-((tert-butyldimethylsilyl)oxy)-2-formylpyrrolidine-1-carboxylateHCID 178418689HCID 178418689, compound

Product 1

HCID 59734597(2R,3S)-N-tert-Butyloxycarbonyl-3-(tert-butyldimethylsilanyloxy)-2-(1-hydroxyethyl)pyrrolidine

Reagents, catalysts & solvents 1

HCID 8857Ethyl AcetateSolvent

Conditions

Temperature
-78 °C

Procedure

To a solution of intermediate 5B (˜0.05 M in THF) at −78° C. was added dropwise MeMgBr (3.0M in Et2O, 3 eq). The reaction was stirred at −78° C. for 1.5-2 h (quench small aliquot in 10% MeOH/DCM, spot TLC-silica gel, 30% EtOAc/Hex-stain with 5% HCl/MeOH, heat and then ninhydrin, heat). Quench reaction by addition of HOAc (3 eq) at −78° C. Warm to RT, dilute with EtOAc and wash with a 1:1 mixture of sat. aq. NaHCO3 and sat aq. NaCl. Back extract aqueous layer. Combine organic extracts, dry over MgSO4, filter and concentrate. Purification by flash chromatography (silica gel, step gradient 0-10-20% EtOAc in hexane) provided the title compound.

Workup

  1. customquench small aliquot in 10% MeOH/DCM
  2. temperaturespot TLC-silica gel, 30% EtOAc/Hex-stain with 5% HCl/MeOH, heat
  3. temperatureninhydrin, heat)
  4. customQuench
  5. customreaction
  6. temperatureWarm to RT
  7. washwash with a 1:1 mixture of sat. aq. NaHCO3
  8. extractionBack extract aqueous layer
  9. dry with materialCombine organic extracts, dry over MgSO4
  10. filtrationfilter
  11. concentrationconcentrate
  12. customPurification by flash chromatography (silica gel, step gradient 0-10-20% EtOAc in hexane)

Sources & evidence

ORD record
ord-d447bb502fb04a80a149ffbc63b1e983
Source dataset
uspto-grants-2009_12
Patent number
US07625923B2

Reaction notes

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