[Br:1][C:2]1[CH:3]=[C:4]([C:8](=O)[CH2:9][F:10])[CH:5]=[CH:6][CH:7]=1.[CH3:12][C:13]([S@:16]([NH2:18])=[O:17])([CH3:15])[CH3:14].C(Cl)Cl>C1COCC1.C(O[Ti](OC(C)C)(OC(C)C)OC(C)C)(C)C>[Br:1][C:2]1[CH:3]=[C:4](/[C:8](=[N:18]\[S@@:16]([C:13]([CH3:15])([CH3:14])[CH3:12])=[O:17])/[CH2:9][F:10])[CH:5]=[CH:6][CH:7]=1
To a round-bottomed flask charged with 1-(3-bromophenyl)-2-fluoroethanone (11.42 g, 52.6 mmol) in THF (100 ml), was added (R)-2-methylpropane-2-sulfinamide (12.75 g, 105 mmol). Then tetraisopropoxytitanium (31.2 ml, 105 mmol) was added into the reaction mixture. The reaction mixture was stirred at ambient temperature under inert atmosphere overnight. The material was poured slowly into a vigourously stirring solution of ice water. The resulting suspension was stirred vigourously for 20 min. Then methylene chloride was added into the mixture and the overall mixture was allowed to stir an additional 30 min. The mixture was filtered through a pad of celite and the filter cake was washed with methylene chloride. The organic layer was separated and the remaining aqueous layer was extracted with methylene chloride three times. The combined organic extracts were washed with brine, dried over magnesium sulfate, filtered and concentrated in-vacuo. The crude material was absorbed onto a plug of silica gel and purified by chromatography through a Redi-Sep pre-packed silica gel column, eluting with a gradient of 0-15% EtOAc/hexane to give (R,E)-N-(1-(3-bromophenyl)-2-fluoroethylidene)-2-methylpropane-2-sulfinamide (9.69 g, 57.5% yield).
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