Ammonium Chloride → (3S,5R)-5-Methyl-3-((4R,5S)-4-methyl-2-oxo-5-phenyl-oxazolidine-3-carbonyl)-octanoic acid tert-butyl ester

HRID 130534Notes

Reaction equation

HRID 130534 reaction equation
[CH3:1][C@@H:2]1[C@H:6]([C:7]2[CH:12]=[CH:11][CH:10]=[CH:9][CH:8]=2)[O:5][C:4](=[O:13])[N:3]1[C:14](=[O:22])[CH2:15][CH2:16][C@H:17]([CH3:21])[CH2:18][CH2:19][CH3:20].C[Si]([N-][Si](C)(C)C)(C)C.[Na+].[C:33]([O:37][C:38](=[O:41])[CH2:39]Br)([CH3:36])([CH3:35])[CH3:34].[Cl-].[NH4+]>C1COCC1>[C:33]([O:37][C:38](=[O:41])[CH2:39][C@@H:15]([C:14]([N:3]1[C@H:2]([CH3:1])[C@H:6]([C:7]2[CH:12]=[CH:11][CH:10]=[CH:9][CH:8]=2)[O:5][C:4]1=[O:13])=[O:22])[CH2:16][C@H:17]([CH3:21])[CH2:18][CH2:19][CH3:20])([CH3:36])([CH3:35])[CH3:34]

Participants

6

Reactant 4

HCID 25517Ammonium ChlorideHCID 79177tert-Butyl bromoacetateHCID 2724254Sodium bis(trimethylsilyl)amideHCID 57160957(4R,5S)-4-Methyl-3-((R)-4-methyl-heptanoyl)-5-phenyl-oxazolidin-2-one

Product 1

HCID 57207445(3S,5R)-5-Methyl-3-((4R,5S)-4-methyl-2-oxo-5-phenyl-oxazolidine-3-carbonyl)-octanoic acid tert-butyl esterYield 71.8%

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent2×

Conditions

Temperature
-50 °C

Procedure

To oxazolidinone 100 (12.1 g, 0.04 mol) in THF (200 ml) at −50° C. was added NaHMDS (48 mL of a 1 M solution in THF). After 30 t-butylbromoaceate (15.6 g, 0.08 mol) was added. The solution was stirred for 4 hours at −50° C. and then warmed to room temperature. After 16 hours a saturated aqueous solution of ammonium chloride was added and the two layers separated. The aqueous phase was extracted with ether and the combined organic phases dried (MgSO4) and concentrated. Flash chromatography (9:1 hexane/EtOAc) gave the product 101 as a white solid 12 g; 72%. [α]D=30.2 (c 1 in CHCl3). 13C NMR (100 MHz; CDCl3) 176.47, 171.24, 152.72, 133.63, 128.87, 125.86, 80.85, 78.88, 55.34, 39.98, 38.77, 38.15, 37.58, 30.60, 28.23, 20.38, 20.13, 14.50, 14.28.

Workup

  1. temperaturewarmed to room temperature
  2. customthe two layers separated
  3. extractionThe aqueous phase was extracted with ether
  4. dry with materialthe combined organic phases dried (MgSO4)
  5. concentrationconcentrated

Sources & evidence

ORD record
ord-9f3ebe445d3a40f4bc390c8496410e8f
Source dataset
uspto-grants-2008_06
Patent number
US07381747B2

Reaction notes

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