Dicyclopropyl ketone → 4-Carbethoxy-5-phenyl-2-vinyl-2,3-dihydrofuran
反応式
[C:1]([C:9]1([C:14]([O:16][CH2:17][CH3:18])=[O:15])[CH2:11][CH:10]1[CH:12]=[CH2:13])(=[O:8])[C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=1.[Cl-].C(C([NH3+])(C(=O)CCCCCCC)C(=O)CCCCCCC)(=O)CCCCCCC.C1(C(C2CC2)=O)CC1>>[C:14]([C:9]1[CH2:11][CH:10]([CH:12]=[CH2:13])[O:8][C:1]=1[C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=1)([O:16][CH2:17][CH3:18])=[O:15]参加物
4
実験手順
4-Carbethoxy-5-phenyl-2-vinyl-2,3-dihydrofuran was obtained in the usual manner by isomerizing ethyl 1-benzoyl-2-vinylcyclopropane-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, essentially pure 4-carbethoxy-5-phenyl-2-vinyl-2,3-dihydrofuran was obtained. The product (B.P. 110° C. @ 0.1 mm Hg: nD25° 1.5570) had a pleasing aroma that was somewhat coumarin-like in odor character. Nuclear magnetic resonance and infrared spectroscopic analysis confirmed the structure ##STR16##