[C:1]([C:5]1[CH:10]=[CH:9][C:8]([NH:11][S:12]([CH3:15])(=[O:14])=[O:13])=[CH:7][CH:6]=1)(=O)[CH2:2][CH3:3].[CH3:16][C:17]([S@:20]([NH2:22])=[O:21])([CH3:19])[CH3:18].[BH4-].[Na+]>C1COCC1.[O-]CC.[Ti+4].[O-]CC.[O-]CC.[O-]CC>[C:17]([S@:20]([NH:22][C@@H:1]([C:5]1[CH:10]=[CH:9][C:8]([NH:11][S:12]([CH3:15])(=[O:14])=[O:13])=[CH:7][CH:6]=1)[CH2:2][CH3:3])=[O:21])([CH3:19])([CH3:18])[CH3:16]To a solution of titanium(IV) ethoxide (2.0 ml) and N-(4-propanoylphenyl)methanesulfonamide (280 mg, 1.2 mmol, Bioorganic & Medicinal Chemistry Letters, 2004, 14(7), 1751-1755) in THF (5.0 ml) was added (R)-(+)-2-methyl-2-propanesulfinamide (149 mg, 1.2 mmol) and the mixture was stirred for 16 hours at 70° C. Upon completion, as determined by TLC, the mixture was cooled to room temperature and then to 0° C. before the reaction mixture was added dropwise to a suspension of sodium borohydride (185 mg, 4.9 mmol) in THF (12 ml) at 0° C. The procedure described in Example 2C was performed to give the title compound (240 mg, 72%) as a yellow oil.
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