反应详情

(3R,4R)-[1-Benzyloxycarbonyl-4-hydroxypyrrolidin-3-yl]methanol (2.50 g), triphenylphosphine (5.74 g) and benzoic acid (2.55 g) were dissolved in tetrahydrofuran (60 mL). While this solution was chilled in a salt/ice bath, diethyl azodicarboxylate (40% toluene solution, 9.53 mL) was added dropwise. The mixture was stirred at 0° C. or below for 1 hour and then at room temperature for 2 hours and was subsequently concentrated under reduced pressure. The resulting residue was purified by silica gel column chromatography (eluant: hexane:ethyl acetate=2:1). The eluted pale brown tar-like material was dissolved in ethanol (60 mL). To this solution, potassium carbonate (4.07 g) in water (30 mL) was added and the mixture was refluxed for 3 hours while being stirred. Subsequently, the reaction mixture was concentrated under reduced pressure and the residue was dissolved in dichloromethane (200 mL). This solution was washed with saturated brine (2×50 mL), dried over anhydrous sodium sulfate, and concentrated under reduced pressure. The resulting residue was purified by silica gel column chromatography (eluant: ethyl acetate:methanol=10:1) to give (3R,4S)-[1-benzyloxycarbonyl-4-hydroxypyrrolidin-3-yl]methanol as a milky white syrup (2.04 g).

1. additionwas added dropwise
2. waitat room temperature for 2 hours
3. concentrationwas subsequently concentrated under reduced pressure
4. customThe resulting residue was purified by silica gel column chromatography (eluant: hexane:ethyl acetate=2:1)
5. dissolutionThe eluted pale brown tar-like material was dissolved in ethanol (60 mL)
6. additionTo this solution, potassium carbonate (4.07 g) in water (30 mL) was added
7. temperaturethe mixture was refluxed for 3 hours
8. stirringwhile being stirred
9. concentrationSubsequently, the reaction mixture was concentrated under reduced pressure
10. dissolutionthe residue was dissolved in dichloromethane (200 mL)
11. washThis solution was washed with saturated brine (2×50 mL)
12. dry with materialdried over anhydrous sodium sulfate
13. concentrationconcentrated under reduced pressure
14. customThe resulting residue was purified by silica gel column chromatography (eluant: ethyl acetate:methanol=10:1)