Reacción #54189

Ecuación de reacción

methanol

5-methyl-2-(2-hydroxy-propyl)furan

chlorine

→

white solid

Rendimiento 30.0%

6-methyl-2-ethyl-3-hydroxy-4H-pyran-4-one

Rendimiento 30.0%

Disolventes

water

Condiciones de reacción

Tratamiento posterior

1. 1
   workup.ADDITIONDuring the addition
2. 2
   Temperaturathe reaction was maintained between -16° and -8° C
3. 3
   workup.ADDITIONWhen addition
4. 4
   Temperaturathe solution was warmed to 80° C.
5. 5
   Temperaturarefluxed for about 3 hours
6. 6
   TemperaturaUpon cooling to room temperature
7. 7
   Extracciónextracted with chloroform (3×100 ml)
8. 8
   LavadoThe combined organic layers were washed with water, brine
9. 9
   Secadodried over magnesium sulfate
10. 10
    FiltraciónThe organic solution was filtered
11. 11
    Otroevaporated
12. 12
    Otroto give a thick dark solid
13. 13
    OtroThe solid was recrystallized twice from methanol

Procedimiento

In a three necked round bottom flask were combined 28 ml of methanol and 38 ml of water. The solution was cooled to -15° C. and 0.166 mole of 5-methyl-2-(2-hydroxy-propyl)furan (J. Org. Chem., 26, 1673, 1960) and 0.416 mole of chlorine were added simultaneously. During the addition, the reaction was maintained between -16° and -8° C. When addition was completed, the solution was warmed to 80° C. and refluxed for about 3 hours. Upon cooling to room temperature, the pH was adjusted to 2.1 and extracted with chloroform (3×100 ml). The combined organic layers were washed with water, brine and dried over magnesium sulfate. The organic solution was filtered and evaporated to give a thick dark solid. The solid was recrystallized twice from methanol to give 8.06 grams (30% yield) of white solid. Sublimation yielded pure product, m.p. 157°-159° C.

Fuente