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

Participants

Reaction Conditions

Reaction Steps

To demonstrate the ability to vary the method of addition, diethyl malonate (160 g; 1.0 mol) was slowly charged to a reactor with external cooling means containing 137.5 g (1.10 mol) trans 1,4-dichlorobutene-2, 125 g (2.0 mol) flaked KOH (90%), 300 cc methylene chloride and 21 g (5 mol %) of tricaprylylmethylammonium chloride. The reaction mixture was stirred during the addition and temperature maintained at 25° C. with external cooling. At the completion of the reaction the resulting crude product obtained following the usual workup procedure was fractionally distilled and 165.3 g diethyl 2-vinylcyclopropane-1,1-dicarboxylate (77.9% yield) recovered. The reaction was repeated using 1/2 and 1/4 the volume of methylene chloride and yields were 77.4% and 72.3%, respectively. While the reaction does proceed when no solvent is employed, the yield of the diethyl ester product is less than optimum.

Provenance & Evidence