Reaktion #456318

Reaktionsgleichung

Benzyloxyacetyl chloride

methylmagnesium iodide

HCl

LDA

ethyl benzoylformate

→

4-hydroxy-5-methyl-5-phenyl-3-phenylmethoxy-2-(5H)-furanone

Ausbeute 20.0%

Lösungsmittel

ether

THF

THF

Reaktionsbedingungen

Aufarbeitung

1. 1
   TemperaturTo a 2-necked flask flame
2. 2
   Sonstigedried under argon with septum
3. 3
   workup.WAITat room temperature for 30 minutes
4. 4
   Temperaturagain cooled to 0° C
5. 5
   workup.STIRRINGthe reaction mixture was stirred at room temperature for 1 hour
6. 6
   Temperaturcooled to -78° C.
7. 7
   SonstigeThe layers were separated
8. 8
   Waschenthe organic phase was washed with 50 mL aqueous 10% HCl solution, 30 mL of H2O
9. 9
   Extraktionextracted with 3×40 mL of saturated NaHCO3 solution
10. 10
    Waschenwashed with 40 mL of ether
11. 11
    Extraktionextracted with 2×80 mL of ether
12. 12
    Waschenwashed with 25 mL of H2O, 25 mL of brine
13. 13
    Trocknendried (MgSO4)
14. 14
    Einengenconcentrated

Vorschrift

To a 2-necked flask flame dried under argon with septum and charged with a solution of 3.6 g (20 mmol) of ethyl benzoylformate in 50 mL of anhydrous THF at -30° C. was slowly added 7 mL (21 mmol) of a 3.0 M solution of methylmagnesium iodide. The reaction mixture was stirred at 0° C. for 45 minutes, then at room temperature for 30 minutes and again cooled to 0° C. Benzyloxyacetyl chloride (3.4 mL, 21 mmol) was added and the reaction mixture was stirred at room temperature for 1 hour, cooled to -78° C. and 33 mL of a 1.5M solution of LDA in THF was added with rapid stirring. The mixture was worked up after 1 hour by the addition of 100 mL of aqueous 10% HCl solution and 300 mL of ether. The layers were separated and the organic phase was washed with 50 mL aqueous 10% HCl solution, 30 mL of H2O, and extracted with 3×40 mL of saturated NaHCO3 solution. The bicarbonate extracts were combined and washed with 40 mL of ether, acidified to pH 1 with 10% aqueous HCl solution, and extracted with 2×80 mL of ether. The organic fractions were combined, washed with 25 mL of H2O, 25 mL of brine, dried (MgSO4), and concentrated leaving 1.2 g (20% yield) of 4-hydroxy-5-methyl-5-phenyl-3-phenylmethoxy-2-(5H)-furanone as a yellow oil.

Quelle