反应详情

温度

83 °C

Employing a procedure similar to that described in Example I, 6.25 gms (0.05 mol) 1,4-dichlorobutene-2 and 8 gms (0.05 mol) diethylmalonate were condensed. The reaction was carried out in 50 mls benzene using 0.11 mol potassium hydroxide and 5 mol percent, based on the diethylmalonate, catalyst (dicyclohexano-18-crown-6). After the reactants were combined and the mild exotherm subsided, the reaction mixture was heated for about 4 hours to a maximum temperature of 83° C. Approximately 4 mls water was removed during the course of the reaction. Upon workup of the reaction mixture, 9.23 gms very light yellow-orange oil was recovered. Vacuum distillation of the crude product yielded pure diethyl 2-vinylcyclopropane-1,1-dicarboxylate in 61% yield. The distillation residue (1.52 gms), consisting primarily of dicyclohexano-18-crown-6, was retained for reuse.

1. customcondensed
2. customApproximately 4 mls water was removed during the course of the reaction
3. customUpon workup of the reaction mixture, 9.23 gms very light yellow-orange oil was recovered
4. distillationVacuum distillation of the crude product