Cyclohexanone → Spiro(5.5)undecan-1-one

Reaktionsgleichung

CC(C)([O-])C.[K+].[C:7]1(=[O:13])[CH2:12][CH2:11][CH2:10][CH2:9][CH2:8]1.Br[CH2:15][CH2:16][CH2:17][CH2:18][CH2:19]Br>C1(C)C=CC=CC=1>[C:7]1(=[O:13])[C:12]2([CH2:19][CH2:18][CH2:17][CH2:16][CH2:15]2)[CH2:11][CH2:10][CH2:9][CH2:8]1

Komponenten

Versuchsvorschrift

To a suspension of potassium tert-butoxide (24.4 g) in toluene (100 mL) was added a solution of cyclohexanone (10.67 g) and 1,5-dibromopentane (25 g) in toluene (50 mL) while stirring. The mixture was stirred at 100° C. for 4 hours. After cooling down to room temperature, the resulting solid was filtered and washed with toluene. The filtrate was concentrated and the residue was purified by column chromatography on silica gel (ethyl acetate:hexane (volume ratio)=1:15) to give spiro[5.5]undecan-1-one (11.85 g).