反应详情

A solution of 5.82 g of lithium diisopropylamide in 30 ml of anhydrous tetrahydrofuran is cooled to -78° C. under an inert atmosphere. Under constant stirring at -78° a solution of 9.84 g of ethyl n-butyl(methyl)phosphinate in 20 ml of anhydrous tetrahydrofuran is added over 15 minutes under a positive pressure of an inert atmosphere via a canula. The resulting pale yellow solution is stirred for 1 hour at -78° and a pre-cooled (-78° C.) solution of 1.89 g of N-tert.-butoxycarbonylglycine methyl ester in 10 ml of anhydrous tetrahydrofuran is added over 5 minutes via a canula. Thin layer chromatography indicates complete reaction after circa 10 minutes. At -78° 4.0 g of glacial acetic acid is added and the mixture is allowed to warm to room temperature. The reaction mixture is diluted with dichloromethane and washed with water. Drying over magnesium sulphate and removal of the solvent in vacuo affords a pale yellow oil. Removal of the excess starting material by distillation and chromatography of the resulting yellow oil on silica gel yields ethyl 3-(N-tert.-butoxycarbonylamino)-2-oxo-propyl(n-butyl)phosphinate as a colourless viscous oil.

1. additionis added over 15 minutes under a positive pressure of an inert atmosphere via a canula
2. additionis added over 5 minutes via a canula
3. customreaction after circa 10 minutes
4. washwashed with water
5. dry with materialDrying over magnesium sulphate and removal of the solvent in vacuo
6. customaffords a pale yellow oil
7. customRemoval of the
8. distillationby distillation and chromatography of the resulting yellow oil on silica gel