Br[C:2]1[CH:7]=[C:6]([O:8][CH3:9])[C:5]([O:10][CH3:11])=[C:4]([O:12][CH3:13])[CH:3]=1.C([Li])CCC.CCCCCC.[Br-].[Mg+2].[Br-].C1(S([CH:37]2[CH2:41][CH2:40][CH:39]([O:42][CH3:43])[O:38]2)(=O)=O)C=CC=CC=1>C1COCC1.[Br-].[Zn+2].[Br-]>[CH3:13][O:12][C:4]1[CH:3]=[C:2]([CH:37]2[CH2:41][CH2:40][CH:39]([O:42][CH3:43])[O:38]2)[CH:7]=[C:6]([O:8][CH3:9])[C:5]=1[O:10][CH3:11]To stirred solution of 1-bromo-3,4,5-trimethoxybenzene (2.47 g, 10 mmol) in THF (20 ml) at -78° C. was added 2.5M n-butyllithium in hexane (4.4 ml, 11 mmol). After 0.75 h the solution was cannulated into a mixture of 1M zinc(II) bromide in THF (11 ml, 11 mmol) and magnesium(II) bromide etherate (2.86 g, 15 mmol) in THF (10 ml) at -78° C. The resulting mixture was allowed to warm to room temperature over 1 h and then sonicated for 0.4 h. A solution of 2-benzenesulphonyl-5-methoxytetrahydrofuran (1.85 g, 7.5 mmol) in THF (10 ml)was added and the mixture stirred at room temperature for 1 h, sonicated for 1 h and stirred overnight. The reaction was quenched by the addition of aqueous ammonium chloride (20 ml). Work up and purification as described for Example 1(b) gave 2-(3,4,5-trimethoxyphenyl)-5 -methoxytetrahydrofuran (0.55 g, 27%) as a colourless oil.
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