反应详情

To a suspension of 7.1 g of sodium hydride (50% suspension in oil) in 220 ml of absolute tetrahydrofuran a solution of 31.5 g of 3-methyl-2-oxo-butylphosphonic acid dimethyl ester in 74 ml of absolute tetrahydrofuran is added in drops at 24° C.; the product is stirred for 1.5 hours and then, at 0° C., 111 ml of a 1.6 molar butyl lithium solution in hexane is added drop by drop and stirred for 20 minutes. A solution of 29 g of 1-bromo-2-pentine in 44 ml of absolute tetrahydrofuran is then added to the above solution drop by drop, stirred for 3 hours at 0° C., neutralized with 3N of hydrochloric acid and concentrated in a vacuum. 50 ml of brine is added; extraction is performed three times, each time with 200 ml of methylene chloride; the organic extract is shaken twice, each time with 50 ml of brine; the product is dried with magnesium sulfate and concentrated by evaporation in a vacuum. After distillation of the residue at 0.6 Torr and 125° C., 23 g of the title compound is obtained in the form of a colorless liquid.

1. additionis added in drops at 24° C.
2. stirringstirred for 20 minutes
3. stirringstirred for 3 hours at 0° C.
4. concentrationconcentrated in a vacuum
5. addition50 ml of brine is added
6. extractionextraction
7. extractionthe organic extract
8. stirringis shaken twice
9. dry with materialthe product is dried with magnesium sulfate
10. concentrationconcentrated by evaporation in a vacuum
11. distillationAfter distillation of the residue at 0.6 Torr and 125° C.