[Br:1][C:2]1[C:3]([C:9](=[O:15])[C:10]([O:12][CH2:13][CH3:14])=[O:11])=[C:4]([CH3:8])[S:5][C:6]=1[CH3:7].[BH4-].[BH4-].[BH4-].[BH4-].[Na+].[Na+].[Na+].[Na+]>O1CCCC1.C(O)C>[Br:1][C:2]1[C:3]([CH:9]([OH:15])[C:10]([O:12][CH2:13][CH3:14])=[O:11])=[C:4]([CH3:8])[S:5][C:6]=1[CH3:7]To a solution of ethyl 2-(4-bromo-2,5-dimethylthiophen-3-yl)-2-oxoacetate (28c) (1 g, 3.56 mmol) in tetrahydrofuran (22.5 mL) and ethanol (5.6 mL) cooled to 0° C. is added sodium tetraborohydride (121.2 mg, 3.20 mmol). The mixture is stirred at 0° C. for 1 hour. The mixture is quenched with HCl (1N) and extracted with ethyl acetate. The organic extract is washed with brine, dried over sodium sulfate, filtered and concentrated to afford the desired alcohol (28d) as a white solid (836 mg, 2.85 mmol, 89%) which was used without further purification.
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