反应详情

To a stirred solution of 62.3 mg (0.25 mmol) of (R)-2-t-butoxycarbonylamino-3-phenylpropanal [synthesized by the method described in Journal of Medicinal Chemistry, 130, 1162 (1987)] in 1.0 ml of THF was added at 0° C., 0.27 ml (5 mmol) of nitromethane, followed by dropwise addition of 0.5 ml (0.025 mmol) of the lanthanum/(R)-1,1'-bi-2-naphthol complex solution (Reference Example 1, 0.05 mol/l). The resultant mixture was stirred at 0° C. for 2 hours. To this solution were added 0.5 ml of 1N hydrochloric acid and 3 ml of water. The mixture was extracted with diethylether, the extract was washed with a saturated aqueous solution of sodium chloride and dried over anhydrous sodium sulfate, and the solvent was distilled off under reduced pressure. The residue was purified by silicagel column chromatography (eluent; n-hexane-ethyl acetate 8:2) to give 47 mg of ⟦(2S,3R)⟧ (2R,3R)-3-t-butoxycarbonylamino-1-nitro-4-phenyl-2-butanol. Yield 60%. ⟦(2S,3R)⟧ (2R,3R)-3-t-Butoxycarbonylamino-1-nitro-4-phenyl-2-butanol:

1. additionwas added at 0° C.
2. extractionThe mixture was extracted with diethylether
3. washthe extract was washed with a saturated aqueous solution of sodium chloride
4. dry with materialdried over anhydrous sodium sulfate
5. distillationthe solvent was distilled off under reduced pressure
6. customThe residue was purified by silicagel column chromatography (eluent; n-hexane-ethyl acetate 8:2)