[CH3:1][O:2][C:3](=[O:24])[C:4]1[C:5](=[C:10]([CH3:23])[C:11](OS(C(F)(F)F)(=O)=O)=[CH:12][C:13]=1[OH:14])[C:6]([O:8][CH3:9])=[O:7].[Cl-].[Li+].[C:27]1([As](C2C=CC=CC=2)C2C=CC=CC=2)C=CC=C[CH:28]=1.C(C([Sn])=C(CCCC)CCCC)CCC.[F-].[K+]>CN1CCCC1=O.CCOC(C)=O>[CH3:1][O:2][C:3](=[O:24])[C:4]1[C:5](=[C:10]([CH3:23])[C:11]([CH:27]=[CH2:28])=[CH:12][C:13]=1[OH:14])[C:6]([O:8][CH3:9])=[O:7]To a solution of 6-hydroxy-3-methyl-4-trifluoromethanesulfonyloxy-phthalic acid dimethyl ester (2.17 g, 5.85 mmol) in N-methylpyrolidinone (15 mL) was added lithium chloride (743 mg, 17.5 mmol) and triphenylarsine (179 mg, 0.585 mmol). Tributylvinyltin (2.04 g, 6.43 mmol) was added followed by tris(tribenzylideneacetone)dipalladium(0)-chloroform adduct (90 mg, 0.087 mmol). The reaction was placed under an atmosphere of nitrogen and heated at 60° C. for 18 hrs. The reaction was cooled to room temperature and poured onto a mixture of ice (20 g), EtOAc (40 mL), and potassium fluoride (1 g). Stirring was continued for 1 hr. The aqueous layer was extracted with EtOAc and the organic extracts filtered through Celite. The combined organic layers were washed with water and dried over sodium sulfate. Filtration and evaporation of solvents in vacuo yielded a crude material, which was purified by silica gel chromatography to provide 1.27 g (87%) of the product as an off-white solid. 1H NMR (300 MHz, CDCl3): δ=2.16 (s, 3H), 3.91 (s, 3H), 3.92 (s, 3H), 5.46 (dd, J=11.1, 1.2 Hz, 1H), 5.72 (dd, J=17.1, 0.9 Hz, 1H), 6.86 (dd, J=17.1, 11.1 Hz, 1H), 7.14 (s, 1H), 10.79 (s, 1H) ppm.
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