C[O:2][C:3]([C:5]1[O:6][C:7]([CH3:19])=[C:8]([CH2:10][O:11][C:12]2[CH:17]=[CH:16][C:15](I)=[CH:14][CH:13]=2)[CH:9]=1)=[O:4].[CH3:20][O:21][C:22]1[CH:23]=[C:24](B(O)O)[CH:25]=[CH:26][C:27]=1[O:28][CH3:29].CN(C)C=O.C([O-])(=O)C.[K+]>O.C1C=CC(P(C2C=CC=CC=2)[C-]2C=CC=C2)=CC=1.C1C=CC(P(C2C=CC=CC=2)[C-]2C=CC=C2)=CC=1.Cl[Pd]Cl.[Fe+2].ClCCl>[CH3:20][O:21][C:22]1[CH:23]=[C:24]([C:15]2[CH:16]=[CH:17][C:12]([O:11][CH2:10][C:8]3[CH:9]=[C:5]([C:3]([OH:2])=[O:4])[O:6][C:7]=3[CH3:19])=[CH:13][CH:14]=2)[CH:25]=[CH:26][C:27]=1[O:28][CH3:29]A stirred mixture of 4-(4-iodo-phenoxymethyl)-5-methyl-furan-2-carboxylic acid methyl ester (20) (0.025 g, 0.067 mmoles), (3,4-dimethoxyphenyl)-boronic acid (0.017 g, 0.093 mmoles), N,N-dimethylformamide (3 mL), potassium acetate (0.026 g) and [1, 1′-bis(diphenylphosphino)ferrocene]dichloropalladium(II), complex with dichloromethane (1:1) (4 mg) was stirred at room temperature under an argon atmosphere for 24 h. The reaction mixture was diluted with water and extracted with ethyl acetate. The extracts were washed with water, dried and concentrated in vacuo. The residue was dissolved in a mixture of tetrahydrofuran/methanol (2:1 by volume) (2.5 mL) and 1.0 M aqueous lithium hydroxide solution (0.5 mL), and stirred for 16 hours. The reaction mixture was acidified to pH=6 using 1M hydrochloric acid and extracted with ethyl acetate (3×25 mL). The extracts were dried, concentrated in vacuo and the residue purified by HPLC (gradient: 30% acetonitrile/70% water containing 0.1% trifluoroacetic acid to 70% acetonitrile/30% water at a rate of 1%/min) to give compound 96 as a solid (15 mg). LC/MS System B; Rt=1.65 mins, m/z (ES−)=367 (M−H for C21H20O5).
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