反应详情

To a solution of methyl 3-hydroxyisoxazole-5-carboxylate (20 g), tert-butyl [(1S)-2-hydroxy-1-methylethyl]carbamate (25 g) and triphenylphosphine (55.1 g) in THF (800 mL) was added dropwise a toluene solution (1.9 M, 110 mL) of diisopropyl azodicarboxylate, and the mixture was refluxed for 5 hr. The reaction mixture was allowed to cool to room temperature, and ethyl acetate was added thereto. The mixture was washed with water and saturated aqueous sodium hydrogen carbonate solution, dried over anhydrous magnesium sulfate, and the solvent was evaporated under reduced pressure. The residue was purified by silica gel column chromatography (hexane/ethyl acetate) to give the title compound (25 g).

1. temperaturethe mixture was refluxed for 5 hr
2. washThe mixture was washed with water and saturated aqueous sodium hydrogen carbonate solution
3. dry with materialdried over anhydrous magnesium sulfate
4. customthe solvent was evaporated under reduced pressure
5. customThe residue was purified by silica gel column chromatography (hexane/ethyl acetate)