Boron trifluoride → Ethyl 5-(1-hydroxybut-3-en-1-yl)-4-methylisoxazole-3-carboxylate

HRID 1478190Notes

Reaction equation

B(F)(F)F.[CH:5]([C:7]1[O:11][N:10]=[C:9]([C:12]([O:14][CH2:15][CH3:16])=[O:13])[C:8]=1[CH3:17])=[O:6].[CH2:18]([Si](C)(C)C)[CH:19]=[CH2:20].C([O-])(O)=O.[Na+]>C(Cl)Cl>[OH:6][CH:5]([C:7]1[O:11][N:10]=[C:9]([C:12]([O:14][CH2:15][CH3:16])=[O:13])[C:8]=1[CH3:17])[CH2:20][CH:19]=[CH2:18]

Participants

Conditions

Temperature: -78 °C

Procedure

A solution of boron trifluoride diethyletherate (54.1 μl, 0.427 mmoL) in DCM (0.3 mL) was cooled to −78° C. In a separate flask a solution of ethyl 5-formyl-4-methylisoxazole-3-carboxylate (Intermediate C) (68 mg, 0.371 mmol) and allyltrimethylsilane (59.0 μl, 0.371 mmol) in DCM were cooled to −78° C. and this solution was added dropwise to the boron trifluoride diethyletherate solution. The reaction mixture was stirred at −78° C. for 1 hour and at room temperature overnight. To the resulting mixture was added a saturated solution of NaHCO3 (aq) (5 mL) and this was extracted with DCM (×3). The combined organic extracts were passed through a phase separating cartridge and the eluent was concentrated under reduced pressure. The crude material was adsorbed onto silica and purification by chromatography eluting with 0-50% EtOAc in iso-hexane afforded the title compound;

Workup

extractionthis was extracted with DCM (×3)
customseparating cartridge
concentrationthe eluent was concentrated under reduced pressure
customThe crude material was adsorbed onto silica and purification by chromatography
washeluting with 0-50% EtOAc in iso-hexane

Sources & evidence

ORD record: ord-9a146f6097494ad1bd8e0136573baf12
Source dataset: uspto-grants-2016_08
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US09403810B2

Reaction notes

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