[CH3:1][C:2]1[S:3][CH:4]=[CH:5][CH:6]=1.[Li]CCCC.CCCCCC.[CH3:18][C:19]1([CH3:31])[CH2:28][C:27](=O)[C:26]2[C:21](=[CH:22][CH:23]=[C:24]([Br:30])[CH:25]=2)[O:20]1>C1COCC1.C(OCC)(=O)C>[CH3:18][C:19]1([CH3:31])[CH:28]=[C:27]([C:4]2[S:3][C:2]([CH3:1])=[CH:6][CH:5]=2)[C:26]2[C:21](=[CH:22][CH:23]=[C:24]([Br:30])[CH:25]=2)[O:20]1To a cold (-78° C.) solution of 2-methylthiophene (820 mg, 8.3 mmol) in THF (16 mL) was added n-BuLi in hexane (1.6M, 4.4 mL, 8.5 mmol). The mixture was warmed to ambient temperature and stirred for 15 minutes. This solution was added to a flask containing cold (-78° C.) solution of 2,2-dimethyl-6-bromo-chroman-4-one (1.08 g, 4.2 mmol) in THF (4 mL). The mixture was stirred and allowed to gradually warm to ambient temperature over 8 hours, and then stirred for an additional 4 hours at ambient temperature. The mixture was diluted with ethyl acetate (200 mL), washed with 10% HCl, brine (20 mL), dried and the solvent was removed by evaporation. The product was purified by chromatography on a silica gel column to afford the title compound as a colorless off.
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