Br[C:2]1[O:6][C:5]([CH:7]=[O:8])=[CH:4][CH:3]=1.[CH2:9](B(O)O)[CH2:10][CH2:11][CH2:12][CH2:13][CH3:14].C(=O)([O-])[O-].[K+].[K+].C1(C)C=CC=CC=1.O>O.C([O-])(=O)C.[Pd+2].C([O-])(=O)C.CC(OC1C=CC=C(OC(C)C)C=1C1C(P(C2CCCCC2)C2CCCCC2)=CC=CC=1)C>[CH2:9]([C:2]1[O:6][C:5]([CH:7]=[O:8])=[CH:4][CH:3]=1)[CH2:10][CH2:11][CH2:12][CH2:13][CH3:14]According to the method of Molander, et. al. (J. Org. Chem. 2009, 74, 3636), a suspension of 5-bromo-2-formylfuran (695 mg, 3.97 mmol), hexylboronic acid (775 mg, 5.96 mmol), potassium carbonate (1.65 g, 11.91 mmol), palladium(II) acetate (18 mg, 0.079 mmol) and RuPhos (74 mg, 0.16 mmol) in 9:1 toluene/water (22 mL) in a pressure-relief vial under argon was heated in a 120° C. bath for 18 h. After cooling to room temperature, the tion mixture was diluted with water (25 mL) and organics extracted with ether (3×50 mL), dried with magnesium sulfate, filtered, and concentrated. The crude product was purified by chromatography on silica gel (10% ethyl acetate in hexanes) to give 5-hexyl-2-formylfuran (665 mg, 93%) as a clear oil. Used without further characterization.
読み込み中…
