Diethyl Malonate → 2-Ethenylcyclopropane-1,1-dicarboxylic acid

Participants

Reaction Steps

A reaction similar to that described in Example 6 was carried out using solid KOH on a larger scale as follows: To a stirred solution of 550 g (4.4 mol) trans 1,4-dichlorobutene-2, 640 g (4.0 mol) diethyl malonate, 80.7 g tricaprylylmethylammonium chloride in 2.4 liters methylene chloride were added over a one-hour period in small portions 498.7 g (8.0 mol) solid potassium hydroxide flakes (90%). The reaction was then heated to reflux for one hour. Potassium salts were removed by successive additions of water to the reaction mixture and siphoning off the aqueous layer until a total of 1.8 liters of water was added. The organic layer was dried over anhydrous sodium sulfate, filtered, concentrated and distilled at reduced pressure. The diethyl ester of 2-vinylcyclopropane-1,1-dicarboxylic acid was obtained in 76.8% yield.

Provenance & Evidence