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

HRID 1167922Notes

Reaction equation

HRID 1167922 reaction equation
C(NC(C)C)(C)C.C([Li])CCC.[CH3:13][C@@H:14]1[C@H:18]([C:19]2[CH:24]=[CH:23][CH:22]=[CH:21][CH:20]=2)[O:17][C:16](=[O:25])[N:15]1[C:26](=[O:35])[CH2:27][CH2:28][C@H:29]([CH3:34])[CH2:30][CH2:31][CH2:32][CH3:33].Br[CH2:37][C:38]([O:40][C:41]([CH3:44])([CH3:43])[CH3:42])=[O:39]>C1COCC1>[C:41]([O:40][C:38](=[O:39])[CH2:37][C@@H:27]([C:26]([N:15]1[C@H:14]([CH3:13])[C@H:18]([C:19]2[CH:24]=[CH:23][CH:22]=[CH:21][CH:20]=2)[O:17][C:16]1=[O:25])=[O:35])[CH2:28][C@H:29]([CH3:34])[CH2:30][CH2:31][CH2:32][CH3:33])([CH3:44])([CH3:43])[CH3:42]

Participants

6

Reactant 4

HCID 7912DiisopropylamineHCID 79177tert-Butyl bromoacetateHCID 57142278(4R,5S)-4-Methyl-3-((R)-4-methyl-octanoyl)-5-phenyl-oxazolidin-2-oneHCID 178418339Butyllithium

Product 1

HCID 57052159(3S,5R)-5-Methyl-3-((4R,5S)-methyl-2-oxo-5-phenyl-oxazolidine-3-carbonyl)-nonanoic acid tert-butyl esterYield 61%

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent2×

Conditions

Temperature
10 °C

Procedure

To a solution of diisopropylamine (1.8 mL, 12.6 mmol) in 30 mL THF at −78° C. was added n-butyl lithium (1.6 M solution in hexanes, 7.6 mL, 12.1 mmol), and the mixture stirred 10 minutes at which time oxazolidinone 137 (3.2 g, 10.1 mmol) in 10 mL THF was added dropwise. The solution was stirred for 30 minutes, t-butyl bromoacetate (1.8 mL, 12.1 mmol) was added quickly dropwise at −50° C., and the mixture was allowed to warm slowly to 10° C. over 3 hours. The mixture was partitioned between Et2O and sat. NH4Cl (aq), the phases were separated, and the organic phase dried (MgSO4), and concentrated. The residue was purified by flash chromatography (16:1 to 8:1 hexanes:EtOAc) to provide 2.65 g (61%) of ester 138 as a colorless crystalline solid, mp=84-86° C. [α]D23+17.1 (c=1.00, CHCl3); 1H NMR (CDCl3): δ 7.34 (m, 5H), 5.62 (d, J=7.3 Hz, 1H), 4.73 (quint, J=6.8 Hz, 1H), 4.29 (m, 1H), 2.67 (dd, J=9.8, 16.4 Hz, 1H), 2.40 (dd, J=5.1, 16.4 Hz, 1H), 1.69 (m, 1H), 1.38 (s, 9H), 1.28 (m, 7H), 1.08 (m, 1H), 0.88 (m, 9H); 13C NMR (CDCl3) δ 176.45, 171.22, 152.71, 133.64, 128.86, 125.86, 80.83, 78.87, 55.33, 40.02, 38.21, 37.59, 36.31, 30.86, 29.29, 28.22, 23.14, 20.41, 14.36, 14.26. Anal. Calcd for C25H37NO5: C, 69.58; H, 8.64; N, 3.25. Found: C, 69.37; H, 8.68; N, 3.05.

Workup

  1. additionwas added dropwise
  2. customThe mixture was partitioned between Et2O and sat. NH4Cl (aq)
  3. customthe phases were separated
  4. dry with materialthe organic phase dried (MgSO4)
  5. concentrationconcentrated
  6. customThe residue was purified by flash chromatography (16:1 to 8:1 hexanes:EtOAc)

Sources & evidence

ORD record
ord-c335fd66a17b4b60a96bf85ce7e05f07
Source dataset
uspto-grants-2003_09
Patent number
US06620829B2

Reaction notes

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