[O:1]1[CH2:6][CH:5]=[C:4](OS(C(F)(F)F)(=O)=O)[CH2:3][CH2:2]1.[CH3:15][O:16][C:17]1[CH:22]=[CH:21][C:20](B2OC(C)(C)C(C)(C)O2)=[CH:19][C:18]=1[N+:32]([O-:34])=[O:33].C(=O)([O-])[O-].[Na+].[Na+]>C1(C)C=CC=CC=1.C(O)C>[CH3:15][O:16][C:17]1[CH:22]=[CH:21][C:20]([C:4]2[CH2:3][CH2:2][O:1][CH2:6][CH:5]=2)=[CH:19][C:18]=1[N+:32]([O-:34])=[O:33]2.0 g Trifluoro-methanesulfonic acid 3,6-dihydro-2H-pyran-4-yl ester (8.6 mmol) and 2.89 g 2-(4-methoxy-3-nitro-phenyl)-4,4,5,5-tetramethyl-[1,3,2]dioxaborolane (10.3 mmol) were dissolved in a mixture of toluene (20 ml) and ethanol (50 ml) 0.35 g of dichloro (1,1′bis-(diphenylphosphine)ferrocene)palladium(II)dichloromethane (0.43 mmol) was added and heated to 85° C. Then aqueous sodium carbonate (2M) (10 ml) was added and the reaction kept at 85° C. for 45 min. After cooling to ambient temperature the reaction was extracted with ethyl acetate/water, the organic phase was dried over sodium sulfate and concentrated. Column chromatography on silica gel (n-heptane/ethyl acetate 4:1) yielded 1.33 g of 4-(4-methoxy-3-nitro-phenyl)-3,6-dihydro-2H-pyran (66%) as a yellow solid; M.p.: 117–120° C.
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