Ammonium Chloride → HCID 22864981, compound

HRID 1078713Notes

Reaction equation

HRID 1078713 reaction equation
[O:1]([C@H:9]1[CH2:13][N:12]([C:14]([O:16][C:17]([CH3:20])([CH3:19])[CH3:18])=[O:15])[C@H:11]([C:21](=[O:27])[CH2:22][C:23]([O:25][CH3:26])=[O:24])[CH2:10]1)[Si:2]([C:5]([CH3:8])([CH3:7])[CH3:6])([CH3:4])[CH3:3].[BH4-].[Na+].[Cl-].[NH4+].C(OCC)(=O)C.O>CO>[O:1]([C@H:9]1[CH2:13][N:12]([C:14]([O:16][C:17]([CH3:18])([CH3:19])[CH3:20])=[O:15])[C@H:11]([C@@H:21]([OH:27])[CH2:22][C:23]([O:25][CH3:26])=[O:24])[CH2:10]1)[Si:2]([C:5]([CH3:6])([CH3:7])[CH3:8])([CH3:4])[CH3:3].[O:1]([C@H:9]1[CH2:13][N:12]([C:14]([O:16][C:17]([CH3:18])([CH3:19])[CH3:20])=[O:15])[C@H:11]([C@H:21]([OH:27])[CH2:22][C:23]([O:25][CH3:26])=[O:24])[CH2:10]1)[Si:2]([C:5]([CH3:6])([CH3:7])[CH3:8])([CH3:4])[CH3:3]

Participants

7

Reactant 4

HCID 25517Ammonium ChlorideHCID 4311764Sodium borohydrideHCID 22728543Water ethylacetateHCID 22864984HCID 22864984, compound

Product 2

HCID 10862338HCID 10862338, compoundYield 21%HCID 22864981HCID 22864981, compoundYield 28%

Reagents, catalysts & solvents 1

HCID 887MethanolSolvent

Procedure

To a solution of (2S,4R)-4-tert-butyldimethylsiloxy-N-tert-butoxycarbonyl-2-(2-methoxycarbonyl-1-oxoethyl)pyrrolidine (402 mg, 1.0 mmol) in methanol (2 ml) was added sodium borohydride (19 mg, 0.5 mmol) under a nitrogen atmosphere under cooling with ice. The mixture was stirred for 30 minutes at the same temperature. To this reaction solution was added saturated aqueous ammonium chloride (about 2 ml). This mixture was poured into ethyl acetate-water (50 ml--50 ml) for liquid separation. The organic layer was washed successively with 10% aqueous citric acid and saturated aqueous sodium chloride, and dried over anhydrous magnesium sulfate. The solvent was removed in vacuo. The residue was purified by silica gel column chromatography [Wakogel™ C-300, heptane-ethyl acetate (3:1)] to obtain (2S,4R)-4-tert-butyldimethylsiloxy-N-tert-butoxycarbonyl-2-[(1S)-2-methoxycarbonyl-1-hydroxyethyl]pyrrolidine (113 mg, yield: 28%, less polar compound) and (2S,4R)-4-tert-butyldimethylsiloxy-N-tert-butoxycarbonyl-2-[(1R)-2-methoxycarbonyl-1-hydroxyethyl]pyrrolidine (86 mg, yield: 21%, polar compound) and a mixture of the two (202 mg, yield: 50%, (1S)-form:(1R)-form=4:6).

Workup

  1. temperatureunder cooling with ice
  2. washThe organic layer was washed successively with 10% aqueous citric acid and saturated aqueous sodium chloride
  3. dry with materialdried over anhydrous magnesium sulfate
  4. customThe solvent was removed in vacuo
  5. customThe residue was purified by silica gel column chromatography [Wakogel™ C-300, heptane-ethyl acetate (3:1)]

Sources & evidence

ORD record
ord-d7e74c006de54473b551b1f1ae4dd350
Source dataset
uspto-grants-1996_08
Patent number
US05550121

Reaction notes

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