Reacción #65056

Ecuación de reacción

benzaldehyde

sodium hydroxide

3-acetyl-5-butyldihydro-2(3H)-furanone

water

→

(E)-3-(phenylmethylene)-5-butyldihydro-2 (3H)-furanone

Rendimiento 64.5%

Disolventes

toluene

Condiciones de reacción

Tratamiento posterior

1. 1
   workup.ADDITIONcharged to a 500 mL flask
2. 2
   Otrofitted with a mechanical stirrer
3. 3
   Otrowas removed in the Dean-Stark trap
4. 4
   TemperaturaThe reaction was further heated
5. 5
   Temperaturaunder reflux for an additional 2.5 hours
6. 6
   TemperaturaThe reaction mixture was then cooled to room temperature
7. 7
   Lavadowashed with 3×80 ml of water
8. 8
   ExtracciónThe water layer was extracted with 50 ml of toluene
9. 9
   LavadoThe toluene solution was then washed with 100 ml of saturated sodium chloride
10. 10
    Secadodried over Na2SO4
11. 11
    Concentraciónconcentrated to 35.4 gms of an orange oil under rotoevaporation
12. 12
    workup.DISTILLATION19.0 gms of this oil was subjected to simple straight takeover distillation (0.04 mm Hg: 25°-147° C.)

Procedimiento

To a mixture of 36.8 g (0.200 mole) of 3-acetyl-5-butyldihydro-2(3H)-furanone in 200 mL of toluene charged to a 500 mL flask fitted with a mechanical stirrer, Dean-Stark trap and an addition funnel was added 8.00 g (0.200 mole) of sodium hydroxide at once. The mixture was vigorously stirred for 10 mins. at room temperature and then heated under reflux for 1 hour while water was removed in the Dean-Stark trap. After the one hour period 23.9 g (0.225 mole) of benzaldehyde was added to the refluxing solution in 4-5 ml aliquats in 1 hour. The reaction was further heated under reflux for an additional 2.5 hours. The reaction mixture was then cooled to room temperature and washed with 3×80 ml of water. The water layer was extracted with 50 ml of toluene and the toluene layers combined. The toluene solution was then washed with 100 ml of saturated sodium chloride and dried over Na2SO4 and concentrated to 35.4 gms of an orange oil under rotoevaporation. 19.0 gms of this oil was subjected to simple straight takeover distillation (0.04 mm Hg: 25°-147° C.) to leave 16 g (64.5% yield) of (E)-3-(phenylmethylene)-5-butyldihydro-2 (3H)-furanone as a viscous liquid. 1HNMR (CDCl3) δ7.5 (m, 6H), 4.56 (pentet, 1H), 3.3 (ddd, 1H), 2.8 (ddd, 1H), 1.9-1.2 (m, 6H), 0.86 (t, 3H).

Fuente