Réaction #80633

ord-f5fd5dca543a47fe83e96dd5f0b27d6c

Conditions de réaction

Conditions détaillées
See reaction.notes.procedure_details.

Traitement

  1. 1
    Autrethe ice bath is removed
  2. 2
    workup.STIRRINGthe solution is stirred for 2 hours
  3. 3
    Autreis recooled to 0° C.
  4. 4
    workup.STIRRINGAfter stirring for 1 hour
  5. 5
    Températurethe reaction is heated
  6. 6
    Températureto reflux for 72 hours
  7. 7
    workup.STIRRINGAfter stirring for 5 minutes
  8. 8
    workup.STIRRINGthe mixture stirred for 24 hours
  9. 9
    Extractionextracted with ether
  10. 10
    SéchageThe ethereal layer is dried over sodium sulfate
  11. 11
    Filtrationfiltered
  12. 12
    Concentrationconcentrated
  13. 13
    AutreThe crude solid is chromatographed on silica gel using mixtures of hexane and isopropanol

Mode opératoire

To a clear solution of Example 34 (10 mmol) in tetrahydrofuran (60 ml) at 0° C., n-BuMgcl (2M solution in THF, 25 ml, 50 mmol) is added over 10 minutes. After stirring for an additional 20 minutes, the ice bath is removed and the solution is stirred for 2 hours. The reaction mixture is recooled to 0° C. and triethylborane (1M solution in THF, 60 ml, 60 mmol) is added. After stirring for 1 hour, the reaction is heated to reflux for 72 hours. The reaction mixture is cooled to room temperature and treated with aqueous sodium acetate (5.5 g in 22 ml water). After stirring for 5 minutes, solid hydroxylamine-O-sulfonic acid (5.5 g) is added and the mixture stirred for 24 hours. The reaction mixture is diluted with water and extracted with ether. The ethereal layer is dried over sodium sulfate, filtered and concentrated. The crude solid is chromatographed on silica gel using mixtures of hexane and isopropanol to give the desired product.

Source

DOI: 10.6084/m9.figshare.5104873.v1Brevet: US05616601uspto-grants-1997_04