Reaktion #1073509

Reaktionsgleichung

n-butyllithium

hexane

4-hydroxy-2-cyclopentenone

→

4-butylcyclopent-2-ene-1,4-diol

Ausbeute 90.0%

Lösungsmittel

tetrahydrofuran

tetrahydrofuran

Reaktionsbedingungen

Aufarbeitung

1. 1
   workup.ADDITION13.8 ml, 22.08 mmmoles) was added dropwise
2. 2
   WaschenThe reaction mixture was washed with 8 ml of tetrahydrofuran
3. 3
   workup.ADDITION40 ml of a saturated aqueous solution of ammonium chloride was added
4. 4
   SonstigeThe organic layer was separated
5. 5
   Extraktionthe aqueous layer was extracted with ethyl acetate (20 ml×6)
6. 6
   TrocknenThe extracts were dried over anhydrous sodium sulfate
7. 7
   Filtrationfiltered
8. 8
   Einengenconcentrated
9. 9
   SonstigeThe residue was chromatographed on a silica gel column (Merck silica gel 30 g; hexane:ethyl acetate=4:1)

Vorschrift

30 ml of tetrahydrofuran was put in a reaction tube and cooled to -78° C., and n-butyllithium (as a 1.6M hexane solution; 13.8 ml, 22.08 mmmoles) was added dropwise. Then a solution of 4-hydroxy-2-cyclopentenone (987 mg; 10.1 mmoles) in 20 ml of tetrahydrofuran was added dropwise over about 20 minutes. The reaction mixture was washed with 8 ml of tetrahydrofuran. After 60 minutes, 40 ml of a saturated aqueous solution of ammonium chloride was added, and the mixture was vigorously shaken. The organic layer was separated, and the aqueous layer was extracted with ethyl acetate (20 ml×6). The extracts were dried over anhydrous sodium sulfate, filtered and concentrated. The residue was chromatographed on a silica gel column (Merck silica gel 30 g; hexane:ethyl acetate=4:1) to obtain 1.55 g (yield about 90%) of 4-butylcyclopent-2-ene-1,4-diol.

Quelle