Reaktion #73700

ord-58055c6c07414816a12415bdd9588a10

Lösungsmittel

Reaktionsbedingungen

Temperatur
-3°CELSIUS
Detaillierte Bedingungen
See reaction.notes.procedure_details.

Aufarbeitung

  1. 1
    Temperaturto warm to room temperature
  2. 2
    TemperaturThe mixture was cooled to ˜3° C.
  3. 3
    Temperaturto warm to room temperature
  4. 4
    workup.STIRRINGstirred 3 hr
  5. 5
    SonstigeThe mixture was quenched by addition saturated NH4Cl solution (5 mL)
  6. 6
    SonstigeThe mixture was partitioned between EtOAc (75 mL) and H2O (5 mL)
  7. 7
    WaschenThe organic phase was washed with brine (25 mL)
  8. 8
    Trocknendried over Na2SO4
  9. 9
    Filtrationfiltered
  10. 10
    Einengenthe solution concentrated under reduced pressure
  11. 11
    Sonstigeto give a yellow-orange oil (crude weight=1.41 g)
  12. 12
    SonstigeThe crude product was absorbed onto silica gel
  13. 13
    WaschenThe column was eluted with hexanes (100 mL), 5% EtOAc/hexanes (200 mL) and 10% EtOAc/hexanes (200 mL)
  14. 14
    EinengenProduct fractions were concentrated under reduced pressure
  15. 15
    Sonstigethe residue dried under high vacuum for 1 hr

Vorschrift

A suspension of methyltriphenylphosphonium bromide (1.31 g, 3.67 mmol, 3.67 mmol, 2.0 equiv) in THF (15 mL) was cooled to ˜−3° C. and 2.5M n-BuLi in hexanes (1.4 mL, 3.5 mmol, 1.9 equiv) was added dropwise at <2° C. The yellow light suspension was allowed to warm to room temperature and stirred 1 hr. The mixture was cooled to ˜3° C. and a solution of 12 (0.67 g, 1.84 mmol, 1.0 equiv) in THF (5 mL) was added at <5° C. The mixture was allowed to warm to room temperature and stirred 3 hr. TLC (25% EtOAc/heptanes) showed the reaction was complete. The mixture was quenched by addition saturated NH4Cl solution (5 mL). The mixture was partitioned between EtOAc (75 mL) and H2O (5 mL). The organic phase was washed with brine (25 mL), dried over Na2SO4, filtered and the solution concentrated under reduced pressure to give a yellow-orange oil (crude weight=1.41 g). The crude product was absorbed onto silica gel using DCM and dry-loaded on a column of silica gel (15 g) packed in hexanes. The column was eluted with hexanes (100 mL), 5% EtOAc/hexanes (200 mL) and 10% EtOAc/hexanes (200 mL). Product fractions were concentrated under reduced pressure and the residue dried under high vacuum for 1 hr to give 0.64 g of 13 as a colorless, viscous oil.

Quelle

DOI: 10.6084/m9.figshare.5104873.v1Patent: US08541521B2uspto-grants-2013_09