C[O:2][C:3]([C:5]1[N:6]=[C:7]([CH2:10][NH:11][C:12]([O:14][C:15]([CH3:18])([CH3:17])[CH3:16])=[O:13])[O:8][CH:9]=1)=O.CC(C[AlH]CC(C)C)C.C(C(C(C([O-])=O)O)O)([O-])=O.[K+].[Na+]>ClCCl>[C:15]([O:14][C:12](=[O:13])[NH:11][CH2:10][C:7]1[O:8][CH:9]=[C:5]([CH2:3][OH:2])[N:6]=1)([CH3:18])([CH3:16])[CH3:17]The ester (178 mg, 0.695 mmol) in 0° C. dichloromethane (8 mL) was treated with DIBAL-H (1 M in dichloromethane, 2.08 mL, 2.08 mmol). The mixture was then stirred at 0° C. for 2 hours before being treated with aqueous 5% sodium potassium tartrate (8 mL). The mixture was stirred rapidly for 30 minutes (until the aqueous and organic layers clarified), and the layers were then separated. The aqueous layer was extracted twice with dichloromethane. The combined organic fractions were then dried over anhydrous sodium sulfate and concentrated. Purification by chromatography on silica gel (5% methanol in dichloromethane) gave (4-hydroxymethyl-oxazol-2-ylmethyl)-carbamic acid tert-butyl ester as an oil (45 mg, 28%). 1H NMR (CDCl3) δ 1.40 (s, 9H), 4.43 (d, 2H, J=5.6 Hz), 4.56 (s, 2H), 5.37 (s, 1H), 7.54 (s, 1H).
読み込み中…
