Hydrogen Peroxide → (2S,3S)-2-tert-butoxycarbonylamino-3-phenyl-pentanoic acid

Participants

Reaction Conditions

Reaction Steps

To a solution of [(1S,2S)-1-((S)-2-oxo-4-phenyl-oxazolidine-3-carbonyl)-2-phenyl-butyl]-carbamic acid tert-butyl ester (4.38 g, 10 mmol) in a mixture of tetrahydrofuran and water (3:1, 60 mL) at −10° C. was added sequentially a solution of hydrogen peroxide in water (11 mL, 100 mmol, 30%) and an aqueous solution (15 mL) of lithium hydroxide monohydrate (1.23 g, 30 mmol). The reaction mixture was stirred at −10° C. and the progress of the reaction was monitored by thin layer chromatography. After 3 hours, TLC analysis indicated almost complete consumption of starting material. Saturated aqueous sodium sulfite solution (100 mL) was added. The mixture was concentrated to half of its original volume under reduced pressure to remove tetrahydrofuran and then extracted with dichloromethane (2×100 mL). The aqueous layer was separated, acidified to pH=2-3 with aqueous citric acid solution and extracted with ethyl acetate (2×300 mL). The organic layers were separated, combined and dried over sodium sulfate, concentrated under reduced pressure and dried in vacuo to give (2S,3S)-2-tert-butoxycarbonylamino-3-phenyl-pentanoic acid as a white foam (1.7 g, 58%).

Provenance & Evidence