反应详情

A solution of 49.6 g. (0.40 mole) dimethyl methylphosphonate (Aldrich) in 500 ml. dry tetrahydrofuran is cooled to -78° in a dry nitrogen atmosphere. To the stirred phosphonate solution is added 188 ml. of 2.34 M n-butyllithium in hexane solution (Alfa Inorganics, Inc.) dropwise over a period of 40 minutes at such a rate that the reaction temperature never rose above -65°. After an additional 5 minutes stirring at -78°, 36.3 g. (0.20 mole) methyl decanoate is added dropwise at a rate that kept the reaction temperature less than -70° (20 minutes). After 1.0 hour at -78° the reaction mixture is allowed to warm to ambient temperature, neutralized with 25 ml. acetic acid and rotary evaporated to a white gel. The gelatinous material is taken up in 75 ml. water, the aqueous phase extracted with 100 ml. portions of chloroform (3x), the combined organic extracts are backwashed (50 cc H2O), dried (MgSO4), and concentrated (water aspirator) to a crude residue and distilled, to give dimethyl 2-oxo-undecylphosphonate.

1. customthe reaction temperature less than -70° (20 minutes)
2. waitAfter 1.0 hour at -78° the reaction mixture is allowed
3. customacetic acid and rotary evaporated to a white gel
4. extractionwater, the aqueous phase extracted with 100 ml
5. dry with materialdried (MgSO4)
6. concentrationconcentrated (water aspirator) to a crude residue
7. distillationdistilled