Diethyl Malonate → Diethyl 2-vinylcyclopropane-1,1-dicarboxylate

Participants

Reaction Steps

The following experiment demonstrates the in situ preparation of the onium compound in the process. In a reaction flask were added 137.5 g (1.1 mol) trans 1,4-dichlorobutene-2, 160.0 g (1.0 mol) diethyl malonate, 600 cc methylene chloride and 6.8 g (5 mol % based on diethyl malonate) N,N-dimethylbenzylamine. The mixture was stirred at ambient temperature for 20 minutes and 124.8 g (2.0 mol) flaked 90% potassium hydroxide then added in small portions over a one-hour period while maintaining the reaction temperature at 25° C. with external cooling. The reaction was then stirred at ambient temperature for four hours. Diethyl 2-vinylcyclopropane-1,1-dicarboxylate (126.6 g; 59.8% yield) was obtained. In a similar manner, 5 mol % tri-n-butylphosphine was employed in the reaction and 69.6% yield diethyl 2-vinylcyclopropane-1,1-dicarboxylate obtained.

Provenance & Evidence