Acetic Acid → Dimethyl (2-oxoheptyl)phosphonate

Participants

Reaction Conditions

Reaction Steps

A solution of 100 g. of dimethyl methylphosphonate in 670 ml. of anhydrous tetrahydrofuran is cooled to -78°C. under an argon atmosphere. To the cold solution are added dropwise under stirring and under argon atmosphere, 495 ml. of a 0.1M solution of n-butyllithium in tetrahydrofuran, maintaining the temperature at -70°C. When the addition is complete the reaction mixture is maintained under the same conditions for 10 additional minutes, a solution of 58 ml. of methyl caproate dissolved in 187 ml. of tetrahydrofuran is then carefully added, maintaining the temperature at -78°C. The reaction mixture is stirred at -78°C. for 2 hours followed by stirring for 4 hours at room temperature. The excess base is neutralized with acetic acid and the solvent is evaporated under high vacuo. The residue is dissolved in ether-water (1:1, 950 ml. each), the ethereal phase is separated, washed with water and dried over magnesium sulfate. The ether is evaporated and the residue is purified by vacuum distillation, thus obtaining the pure dimethyl 2-oxoheptylphosphonate.

Provenance & Evidence