Toluene → HCID 12093580, Verbindung
Reaktionsgleichung
[CH:1](=[C:4]1[CH2:8][CH2:7][CH2:6][C:5]1=[O:9])[CH2:2][CH3:3].B(F)(F)F.[CH2:14]=[CH:15][C:16](=C)[CH3:17].[C:19]1(C)C=CC=CC=1>>[CH2:15]([CH:16]1[C:4]2([C:5](=[O:9])[CH2:6][CH2:7][CH2:8]2)[CH2:1][CH:2]=[C:3]([CH3:19])[CH2:17]1)[CH3:14]Komponenten
5
Versuchsvorschrift
A solution of propylidene cyclopentanone (124 g; 1 mol) in toluene (124 g) was cooled to 0° C. BF3 etherate (10 ml) were added at 0° C. over 10 minutes. Isoprene (168 g; 2.47 mol), dissolved in toluene (168 g) was then added dropwise over 3 hours at 0° C. Stirring was continued at 0° C. for 3.5 hours. Usual work-up (see above) afforded 198 g of a crude product as a mixture of isomer (ratio 5/4/91). Distillation through a Vigreux column afforded 165 g of 96% pure cycloadduct (yield: 86%).