Diethyl Ether → 2-(7-Hydroxyheptyl)cyclopent-2-en-1-one

Temperatur

100 °C

A mixture of 7-(2-tetrahydropyranyloxy)heptanal (22 g) and 1-morpholinocyclopentene (21.4 g), i.e. the morpholine enamine of cyclopentanone, in benzene (25 ml) was heated under reflux for 12 hours under nitrogen, and the water liberated was continuously removed with a Dean and Stark head. Benzene (10 ml) and then, dropwise, 18% hydrochloric acid (28 ml) were added and the mixture was stirred for 2 hours. The organic layer was separated and evaporated. Concentrated hydrochloric acid (72 ml) and butanol (300 ml) were added to the residue. The mixture was heated at 100° C. for 1 hour, and then the solution was concentrated to give an oil. Diethyl ether was added and the ether solution was washed with aqueous sodium bicarbonate and then water, and dried over sodium sulphate. The solvent was evaporated and the residue was distilled under reduced pressure to give 2-(7-hydroxyheptyl)cyclopent-2-enone (11.7 g), b.p. 125°-170° C./0.15 mm Hg, nD25 =1.490, λmax 228 mμ (ethanol).

1. temperatureunder reflux for 12 hours under nitrogen
2. customthe water liberated was continuously removed with a Dean and Stark head
3. additionBenzene (10 ml) and then, dropwise, 18% hydrochloric acid (28 ml) were added
4. customThe organic layer was separated
5. customevaporated
6. additionConcentrated hydrochloric acid (72 ml) and butanol (300 ml) were added to the residue
7. concentrationthe solution was concentrated
8. customto give an oil
9. washthe ether solution was washed with aqueous sodium bicarbonate
10. dry with materialwater, and dried over sodium sulphate
11. customThe solvent was evaporated
12. distillationthe residue was distilled under reduced pressure

ORD-Eintrag

ord-9e4474fc85314902978f35ec2cf72e32

Quelldatensatz

uspto-grants-1979_10

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US04171375