[Mg].BrCCBr.Br[C:7]1[CH:8]=[C:9]([O:15][CH3:16])[C:10]([O:13][CH3:14])=[CH:11][CH:12]=1.C1(S([CH:26]2[CH2:30][CH2:29][CH:28]([O:31][CH3:32])[O:27]2)(=O)=O)C=CC=CC=1>C1COCC1.[Zn+2].[Br-].[Br-]>[CH3:16][O:15][C:9]1[CH:8]=[C:7]([CH:26]2[CH2:30][CH2:29][CH:28]([O:31][CH3:32])[O:27]2)[CH:12]=[CH:11][C:10]=1[O:13][CH3:14]
Magnesium (2.18 g, 0.091 M) was placed in a 3-necked flask containing dry THF (10 ml) and 1,2-dibromoethane (0.2 ml). A solution of 4-bromoveratrole (18.0 g, 0.086 M) in THF (50 ml) was added dropwise, warming to initiate reaction. The resulting solution was heated at reflux for 0.75 h then cooled to room temperature and cannulated into a 1M solution of ZnBr2 in THF (50 ml, 0.05 M) and stirred for 0.5 h at room temperature. A solution of 2-benzenesulphonyl-5-methoxytetrahydrofuran (10.0 g, 0.041 M) in THF (50 ml) was added dropwise to the pale yellow suspension and the mixture allowed to stir at room temperature for 20 h. Reaction was quenched by addition of 1N HCl (50 ml), and extracted with ether (2×100 ml). The organics were combined washed with water (50 ml) dried (Na2SO4) and evaporated. Flash column chromatography (flash silica gel, hexane:ethyl acetate (3:2)) gave 2-(3,4-dimethoxyphenyl)-5-methoxytetrahydrofuran (8.0 g, 82%) as a yellow oil (rf 0.28).
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