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

HRID 1829827Notes

Reaction equation

HRID 1829827 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 (4R,5S)-4-methyl-3-((R)-4-methyl-heptanoyl)-5-phenyl-oxazolidin-2-one (12.1 g, 0.04 mol) in THF (200 ml) at −50° C. was added sodium bis(trimethylsilyl)amide (48 mL of a 1 M solution in THF). After 30 min 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 (3S,5R)-5-methyl-3-((4R,5S)-4-methyl-2-oxo-5-phenyl-oxazolidine-3-carbonyl)-octanoic acid tert-butyl ester as a white solid 12 g; 72%. [α]D=+30.2 (c 1 in CHCl3). 13C NMR (100 MHz; CDCl3) δ 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-fd5a4f2a00294ab4b3d7dab0fca65345
Source dataset
uspto-grants-2006_06
Patent number
US07064147B2

Reaction notes

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