Diethyl diallyl malonate

Very recently, Leitner has reported cationic nickel(n) catalyst systems for the cycloisomerization of diethyl diallyl malonate that shows high activities and regioselectivities for the formation of diethyl 3-methylene-4-methylcyclo-pentane-l,l-dicarboxylate with ee values up to 80% when using Wilke s azaphospholene ligand.355... 

Preparation of the intermediate for Allobarbitone (diethyl diallyl malonate). Diethyl malonate is dissolved in anhydrous alcohol and treated with one mole of clean sodium meted per every one mole of the ester. To this solution add one mole of allyl chloride and reflux for about 4 hours. Another equimolar ratio (1 mole of sodium per mole of ester) of sodium is added, followed by the same ratio of allyl chloride (1 mole per 1 mole), and this mixture is boiled for 2 hours. The alcohol is removed by distillation and the ester is extracted with benzene and distilled or evaporated in vacuo, recrystallized with a suitable "dry" solvent, and filtered. Evaporate again to remove traces of solvent. Keep this product, and any other substances that require dry reagents or solvents, stored away from contact with the atmosphere. When evaporating, filter the air coming into the evaporating vessel with a suitable drying agent. Use a little common sense. 

Further modification in snpport of the ruthenium carbene complex with ionic liquid media was described by Wakamatsu et al. [54]. The RCM of diethyl diallyl-malonate using a new catalyst was carried out under an argon atmosphere in the presence of 5 mol% catalyst in CHjClj/[bmim]BF (9 1) at room temperature. The starting material was consumed after 0.5 h to provide a product with 94% yield (Scheme 17.8). Continuous fast conversion was observed, and reliable reusability was realized by the fifth cycle. 

Scheme 7. RCM of diethyl-diallyl-malonate to give the diethyl ester of 3-cyclopentene-l,l-dicarboxylic acid.

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