Reaktion #3005

Reaktionsgleichung

potassium carbonate

benzyl chloride

4-hydroxy-6-methyl-2H-pyran-2-one

18-crown-6

→

4-Benzyloxy-6-methyl-2H-pyran-2-one

Lösungsmittel

dimethyl-formamide

Reaktionsbedingungen

Aufarbeitung

1. 1
   Filtrationfiltered
2. 2
   Waschenthe residue was washed well with ethyl acetate
3. 3
   SonstigeThe combined filtrates were extensively evaporated in a vacuum
4. 4
   workup.ADDITIONsubsequently poured onto ice water
5. 5
   SonstigeThe aspirated precipitate was recrystallized from t-butylmethyl ether
6. 6
   Sonstigeafter drying

Vorschrift

124.4 g (0.900 mol) potassium carbonate and 63 ml (0.547 mol) benzyl chloride were added in succession to a solution of 56.7 g (0.450 mol) 4-hydroxy-6-methyl-2H-pyran-2-one and 1.0 g (0.004 mol) 18-crown-6 in 900 ml anhydrous dimethyl-formamide. It was stirred vigorously for 4.5 hours at an internal temperature of 70°-75° C. It was suction filtered and the residue was washed well with ethyl acetate. The combined filtrates were extensively evaporated in a vacuum and subsequently poured onto ice water. The aspirated precipitate was recrystallized from t-butylmethyl ether after drying. 69.0 g (71%) V, melting point 92°-93° C.

Quelle