Reaktion #79367

Reaktionsgleichung

tetrahydro-4H-pyran-4-one

magnesium

4-benzyloxy bromobenzene

→

4-(4-benzyloxyphenyl)tetrahydro-2H-pyran-4-ol

Ausbeute 55.1%

Lösungsmittel

THF

Reaktionsbedingungen

Aufarbeitung

1. 1
   SonstigeIn a 100 ml round-bottomed flask was placed
2. 2
   Sonstigeover 15 min
3. 3
   Temperaturwith occasional heating by a heat gun
4. 4
   workup.ADDITIONAfter the addition
5. 5
   Temperaturupon cooling in an ice-water bath
6. 6
   workup.STIRRINGAfter stirring for 30 min
7. 7
   Sonstigethe solvent was removed under reduced pressure
8. 8
   workup.ADDITIONdiluted with AcOEt and sat. NH4Cl aq. The organic phase
9. 9
   Sonstigewas separated
10. 10
    Einengenconcentrated
11. 11
    Sonstigechromatographed on silica gel eluting with 40% AcOEt/hexanes

Vorschrift

In a 100 ml round-bottomed flask was placed magnesium turnings (1.85 g, 76.1 mmol), which was stirred under vacuum without solvent overnight. To it were slowly added anhydrous THF 40 ml and 4-benzyloxy bromobenzene (10 g, 38 mmol) over 15 min with occasional heating by a heat gun to keep the Grignard reagent formation going. After the addition was complete, the resulting gray slurry was stirred for 1 hr at 60° C. To it was added tetrahydro-4H-pyran-4-one (3.5 ml, 38 mmol) upon cooling in an ice-water bath. After stirring for 30 min, the solvent was removed under reduced pressure and diluted with AcOEt and sat. NH4Cl aq. The organic phase was separated, concentrated, and chromatographed on silica gel eluting with 40% AcOEt/hexanes to give 4-(4-benzyloxyphenyl)tetrahydro-2H-pyran-4-ol 5.95 g (55%).

Quelle