Dicyclopropyl ketone → 4-Carbethoxy-5-phenyl-2-vinyl-2,3-dihydrofuran
Reaktionsgleichung
[CH:1]([CH:3]1[CH2:5][C:4]1([C:11](=[O:18])[C:12]1[CH:17]=[CH:16][CH:15]=[CH:14][CH:13]=1)[C:6]([O:8][CH2:9][CH3:10])=[O:7])=[CH2:2].[Cl-].C(C([NH3+])(C(=O)CCCCCCC)C(=O)CCCCCCC)(=O)CCCCCCC.C1(C(C2CC2)=O)CC1>>[C:6]([C:4]1[CH2:5][CH:3]([CH:1]=[CH2:2])[O:18][C:11]=1[C:12]1[CH:17]=[CH:16][CH:15]=[CH:14][CH:13]=1)([O:8][CH2:9][CH3:10])=[O:7]Komponenten
4
Versuchsvorschrift
4-Carbethoxy-5-phenyl-2-vinyl-2,3-dihydrofuran was obtained in the usual manner by isomerizing ethyl 2-vinyl-1-benzoylcyclopropane-1-carboxylate. To catalyze the isomerization, tricaprylylmethylammonium chloride was employed at a 20 percent weight level. The mixture was heated at 150° C. for about two hours after which time only about 7 percent of the cyclopropyl ketone remained. After two distillations of the resulting isomerized product, essentially pure 4-carbethoxy-5-phenyl-2-vinyl-2,3-dihydrofuran was obtained (B.P. 110° C. @ 0.1 mm Hg; nD25° 1.5570). The product had a pleasing aroma that was somewhat coumarin-like in odor character.