Potassium Phosphate, Tribasic → [(5S)-3-(5-Bromopyridin-2-yl)-4,5-dihydroisoxazol-5-yl]methyl butyrate
Reaktionsgleichung
[C:1]([O:6][CH2:7][CH:8]1[O:12][N:11]=[C:10]([C:13]2[CH:18]=[CH:17][C:16]([Br:19])=[CH:15][N:14]=2)[CH2:9]1)(=[O:5])[CH2:2][CH2:3][CH3:4].P([O-])([O-])([O-])=O.[K+].[K+].[K+]>CC(C)=O>[C:1]([O:6][CH2:7][C@H:8]1[O:12][N:11]=[C:10]([C:13]2[CH:18]=[CH:17][C:16]([Br:19])=[CH:15][N:14]=2)[CH2:9]1)(=[O:5])[CH2:2][CH2:3][CH3:4]Komponenten
4
Edukt 2
Produkt 1
Reagenzien, Katalysatoren, Lösungsmittel 1
Versuchsvorschrift
Racemic [3-(5-bromopyridin-2-yl)-4,5-dihydroisoxazol-5-yl]methyl butyrate (Intermediate 9, 80 g, 0.244 mol) was dissolved in acetone (4 L), and 0.1 M potassium phosphate buffer (pH˜7) (4 L) was added with vigorous stirring to give a clear yellow solution. PS-lipase (1.45 g, Sigma cat no L-9156) was added and the mixture was gently stirred at ambient temp. for 42 hrs. The solution was divided into 3 equal volumes of ˜2.6 L and each was extracted with dichloromethane (2×1 L), the pooled organic phases were dried over sodium sulfate and evaporated. The unreacted [(5S)-3-(5-bromopyridin-2-yl)-4,5-dihydroisoxazol-5-yl]methyl butyrate was isolated via flash column chromatography (9:1 hexane:ethyl acetate) as a clear yellow oil, 36.4 g (45.5%).