Hydrochloric Acid → 4-Hydroxy-4-methyl-5-(prop-2-en-1-yl)cyclopent-2-en-1-one

Temperature

40 °C

In a reaction vessel, water (150 ml) and tri-n-octylmethylammonium chloride (450 mg) were charged, and the pH value was adjusted to 5.5 with an aqueous 1/3 N HCl solution and an aqueous 1/3 N NaOH solution. Then, 5-methyl-2-furylallylcarbinol (11.0 g) was added thereto, and the temperature was elevated up to 100° C. to reflux. The mixture was stirred under reflux for 7 hours while maintaining a pH value of 5 to 5.5 by the addition of an aqueous 1/3 N NaOH solution and an aqueous 1/3 N HCl solution. After cooling to 40° C., sodium chloride (30 g) was added, and the mixture was extracted with toluene (70 ml) five times. From the extract, toluene was removed by distillation at 60° C. under reduced pressure to give an oily substance (10.1 g), which was subjected to chromatography on silica gel (100 g) with a mixture of ethyl acetate-n-hexane (1:2 by volume) as the developing solvent to obtain 2-allyl-3-hydroxy-3-methyl-4-cyclopentenone (7.1 g). Yield, 64.5%.

1. customwas elevated up to 100° C.
2. temperatureto reflux
3. temperatureunder reflux for 7 hours
4. temperaturewhile maintaining a pH value of 5 to 5.5
5. extractionthe mixture was extracted with toluene (70 ml) five times
6. customFrom the extract, toluene was removed by distillation at 60° C. under reduced pressure
7. customto give an oily substance (10.1 g), which

ORD record

ord-7a2f7977e2b24c78a063cc12662764ef

Source dataset

uspto-grants-1982_10

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US04356326