2-ethenylcyclopropane-1,1-dicarboxylic acid

Conditions: temp:185.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: Ethylene glycol (0.2 mols) and dimethyl 2-vinylcyclopropane-1,1-dicarboxylate (0.2 mols) were combined with 0.1 gms dibutyltin diacetate and 0.1 gms hydroquinone. The temperature was gradually raised to 185° C. over a 3 hour period and then maintained for an additional 41/2 hours during which time about 3.2 gms methanol was collected. The temperature was then reduced to about 80° C. and a vacuum (0.1 mm Hg) pulled on the system to remove final traces of volatile products. The resulting light viscous oil (38.5 gms) contained some monomeric product but consisted primarily of oligomeric products of up to about 5 repeating units. A portion of the product containing 5% benzoin isobutyl ether was spread on a glass plate and upon irradiation with an ultraviolet light source provided a transparent, tack-free, resilient polymer film. Similar products are obtained when 2-vinylcyclopropane-1,1-dicarboxylic acid is esterified with ethylene glycol and diethylene glycol. was collected was then reduced to about 80° C. to remove final traces of volatile products A portion of the product containing 5% benzoin isobutyl ether was spread on a glass plate and upon irradiation with an ultraviolet light source provided a transparent, tack-free, resilient polymer film

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: 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. A reaction similar to The reaction was then heated to reflux for one hour Potassium salts were removed by successive additions of water to the reaction mixture was added The organic layer was dried over anhydrous sodium sulfate filtered concentrated distilled at reduced pressure