Triethylborane → HCID 68823743, compound

HRID 1455581Notes

Reaction equation

HRID 1455581 reaction equation
C(B(CC)CC)C.[CH3:8][C:9]1[O:13][N:12]=[C:11]([C:14]2[O:18][CH:17]=[N:16][CH:15]=2)[CH:10]=1.[Li]CCCC.[C:24]([O:28][C:29](=[O:31])[NH2:30])([CH3:27])([CH3:26])[CH3:25].[O:32]1[CH2:36][CH2:35][CH2:34][CH2:33]1>>[C:24]([O:28][C:29](=[O:31])[NH:30][C@H:34]([CH:33]([OH:32])[C:17]1[O:18][C:14]([C:11]2[CH:10]=[C:9]([CH3:8])[O:13][N:12]=2)=[CH:15][N:16]=1)[CH2:35][CH3:36])([CH3:27])([CH3:26])[CH3:25]

Participants

6

Reactant 5

HCID 7357TriethylboraneHCID 8028Tetrahydrofuran2×HCID 77922tert-Butyl carbamateHCID 45117994HCID 45117994, compoundHCID 178418339Butyllithium

Product 1

HCID 68823743HCID 68823743, compound

Procedure

Triethylborane (1M in THF, 12 mL, 12 mmol) is added to a solution of 5-Methyl-3-oxazol-5-yl-isoxazole (1.8 g, 12 mmol) in 40 mL of dry Tetrahydrofuran and the mixture is stirred at room temperature for 15 minutes. The mixture is cooled to −78° C., nBuLi (2.5M in Hexanes, 4.8 mL, 12 mmol) is added drop wise and the mixture is stirred at −78° C. for 15 minutes. A solution of (S)-1-Formyl-propyl)-carbamic acid tert-butyl ester (898.7 mg, 4.8 mmol) in 15 mL of dry tetrahydrofuran is added drop wise and the reaction mixture is stirred at −78° C. for 3 hours, then let warm to −30° C. and quenched with acetic acid in ethanol (4%, 250 mL), stirring continued for 2 hours, while warming to room temperature. The reaction is concentrated under reduced pressure; the residue is dissolved in diethyl ether (250 mL) and stirred for 1.5 hours at room temperature. The precipitate is filtered; the filtrate is concentrated under reduced pressure. Column chromatography on silica eluting with a mixture of methylene chloride and ethyl acetate gives the title compound as a solid (830 mg).

Workup

  1. temperatureThe mixture is cooled to −78° C.
  2. stirringthe mixture is stirred at −78° C. for 15 minutes
  3. stirringthe reaction mixture is stirred at −78° C. for 3 hours
  4. temperaturelet warm to −30° C.
  5. customquenched with acetic acid in ethanol (4%, 250 mL)
  6. stirringstirring
  7. waitcontinued for 2 hours
  8. temperaturewhile warming to room temperature
  9. concentrationThe reaction is concentrated under reduced pressure
  10. dissolutionthe residue is dissolved in diethyl ether (250 mL)
  11. stirringstirred for 1.5 hours at room temperature
  12. filtrationThe precipitate is filtered
  13. concentrationthe filtrate is concentrated under reduced pressure
  14. additionColumn chromatography on silica eluting with a mixture of methylene chloride and ethyl acetate

Sources & evidence

ORD record
ord-497f3558d4f8423e836987aba9ebd4de
Source dataset
uspto-grants-2009_01
Patent number
US07482448B2

Reaction notes

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