反应详情

To a solution of trans-tert-butyl 1-benzyl-2-oxooctahydro-6H-pyrido[3,4-b][1,4]oxazine-6-carboxylate (126 g, 346 mmol) in anhydrous THF (2 L) was added borane methylsulfide complex (109 mL, 1.038 mol) drop wise at 0° C. The mixture was stirred at room temperature overnight. Methanol (300 mL) was added to the mixture at room temperature and heated to reflux for 1 h. The mixture was washed with saturated NaHCO3 and brine, dried over sodium sulfate, and concentrated under reduced pressure. The residue was purified by silica gel chromatography to afford tert-butyl 1-benzyloctahydro-6H-pyrido[3,4-b][1,4]oxazine-6-carboxylate as a mixture of trans diastereomers.

1. temperatureheated
2. temperatureto reflux for 1 h
3. washThe mixture was washed with saturated NaHCO3 and brine
4. dry with materialdried over sodium sulfate
5. concentrationconcentrated under reduced pressure
6. customThe residue was purified by silica gel chromatography