[Br:1][C:2]1[CH:7]=[CH:6][C:5]([C:8]2[CH2:12][CH:11]([CH2:13][OH:14])[O:10][N:9]=2)=[CH:4][CH:3]=1.C1(P(C2C=CC=CC=2)C2C=CC=CC=2)C=CC=CC=1.O[C:35]1[CH:39]=[CH:38][O:37][N:36]=1.CC(OC(/N=N/C(OC(C)C)=O)=O)C>O1CCCC1>[Br:1][C:2]1[CH:3]=[CH:4][C:5]([C:8]2[CH2:12][CH:11]([CH2:13][O:14][C:35]3[CH:39]=[CH:38][O:37][N:36]=3)[O:10][N:9]=2)=[CH:6][CH:7]=1(5RS)-3-(4-Bromophenyl)-5-hydroxymethyl-4,5-dihydro-isoxazole (3.07 g, 12 mM), triphenylphosphine (3.78 g, 14.4 mM) and 3-hydroxyisoxazole (1.02 g, 12 mM) were dissolved in anhydrous tetrahydrofuran (50 ml), cooled to 0° with stirring under nitrogen, and treated with diisopropylazodicarboxylate (2.71 g, 13.4 mM). Stirring was continued for 18 hours, and the mixture evaporated to dryness. The residue was chromatographed on a 90 g Biotage silica column, eluting with 25% ethyl acetate in isohexane, appropriate fractions combined, and chromatographed again on a 40 g Biotage silica column, eluting with 5% methanol in dichloromethane. Appropriate fractions were combined to give the desired product (2.15 g). MS (ESP): 323 (MH+) for C13H11BrN2O3
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