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

HRID 28429Notizen

Reaktionsgleichung

Reaktionsgleichung von HRID 28429
[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]

Komponenten

6

Edukt 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

Produkt 1

HCID 57207445(3S,5R)-5-Methyl-3-((4R,5S)-4-methyl-2-oxo-5-phenyl-oxazolidine-3-carbonyl)-octanoic acid tert-butyl esterAusbeute 71,8 %

Reagenzien, Katalysatoren, Lösungsmittel 1

HCID 8028TetrahydrofuranLösungsmittel2×

Reaktionsbedingungen

Temperatur
-50 °C

Versuchsvorschrift

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%. [a]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.

Aufarbeitung

  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

Quellen und Nachweise

ORD-Eintrag
ord-775d6eb6009242fc9d2ebddbd03eb751
Quelldatensatz
uspto-grants-2008_09
Patentnummer
US07419981B2

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