反应详情

温度

0 °C

Benzylphosphinic acid (2.3 g, 15 mmol) in 150 mL of dry dichloromethane was cooled to 0° C. under a nitrogen atmosphere. Triethylamine (6.5 g, 65 mmol) was added followed by trimethylsilyl chloride (5.8 g, 54 mmol) while the reaction temperature was maintained at 0° C. After 30 minutes dibenzyl 2-methylene-pentanedioate (2) (4.4 g, 13.6 mmol) in 20 mL of dichloromethane was added over 5 minutes. The reaction mixture was allowed to warm to room temperature and stirred overnight. The clear solution was cooled to 0° C. and quenched with 5% hydrochloric acid followed by removal of the organic layer. The organic layer was washed with 5% hydrochloric acid and with brine, dried (MgSO4) and evaporated to give a clear yellow liquid. Purification by flash chromatography and elution with 1:1 hexane/ethyl acetate containing 10% acetic acid yielded 2.0 g (28%) of benzyl[2,4-di(benzyloxycarbonyl)butyl]-phosphinic acid (3, R=CH2Ph, R1 =H) as a clear light yellow oil. R.function. 0.37 (1:1 Hexane/EtOAc, 10% AcOH).

1. temperatureto warm to room temperature
2. temperatureThe clear solution was cooled to 0° C.
3. customquenched with 5% hydrochloric acid
4. customfollowed by removal of the organic layer
5. washThe organic layer was washed with 5% hydrochloric acid and with brine
6. dry with materialdried (MgSO4)
7. customevaporated
8. customto give a clear yellow liquid
9. customPurification
10. washby flash chromatography and elution with 1:1 hexane/ethyl acetate containing 10% acetic acid