[CH:1]1([OH:6])[CH2:5][CH2:4][CH2:3][CH2:2]1.[H-].[Na+].Br[CH2:10][C:11]1[C:15]([C:16]([O:18][CH3:19])=[O:17])=[C:14]([CH:20]([CH3:22])[CH3:21])[O:13][N:12]=1>C1COCC1>[CH:1]1([O:6][CH2:10][C:11]2[C:15]([C:16]([O:18][CH:19]3[CH2:3][CH2:2][CH2:1][CH2:5]3)=[O:17])=[C:14]([CH:20]([CH3:22])[CH3:21])[O:13][N:12]=2)[CH2:5][CH2:4][CH2:3][CH2:2]1A solution of cyclopentanol (0.44 mL, 4.8 mmol), in THF (10 mL), was stirred at 0° C. as sodium hydride 60% oil dispersion (192 mg, 4.8 mmol) was added. The solution was allowed to stir for 30 minutes. A solution of methyl 3-(bromomethyl)-5-(1-methylethyl)-4-isoxazolecarboxylate (500 mg, 1.91 mmol), in THF (5 mL) was then added and the resulting solution was allowed to warm to room temperature and stir for 3 hours. The solution was then partitioned between brine and ethyl acetate. The organic layer was dried with MgSO4, filtered and concentrated. The residue purified by chromatography (silica gel, hexane to 1:4 ethyl acetate:hexanes). Fractions containing the product were combined and concentrated to yield cyclopentyl 3-[(cyclopentyloxy)methyl]-5-(1-methylethyl)-4-isoxazolecarboxylate (94 mg, 15%). 1H NMR (400 MHz, DMSO-d6): δ 5.29-5.26 (m, 1H), 4.54 (s, 2H), 3.98 (m, 1H), 3.64 (septet, 7 Hz, 1H), 1.85 (m, 2H), 1.72-1.56 (m, 12H), 1.47-1.40 (m, 2H), 1.25 (d, J=7 Hz, 6H). ESI-LCMS m/z 322 (M+H)+.
Wird geladen…
