[CH3:1][C@H:2]1[O:7][S:6](=[O:8])[N:5]([C:9]([O:11][C:12]([CH3:15])([CH3:14])[CH3:13])=[O:10])[CH2:4][CH2:3]1.I([O-])(=O)(=O)=[O:17].[Na+].Cl.CCOC(C)=O>C(#N)C.O>[CH3:1][C@H:2]1[O:7][S:6](=[O:17])(=[O:8])[N:5]([C:9]([O:11][C:12]([CH3:14])([CH3:13])[CH3:15])=[O:10])[CH2:4][CH2:3]1To a solution of tert-butyl (6R)-6-methyl-1,2,3-oxathiazinane-3-carboxylate 2-oxide (2.3 g, 9.6 mmol) in acetonitrile (25 mL) and water (15 mL) cooled to 0° C. is added sodium periodate (3.1 g, 14.3 mmol) in one portion. After 5 min, the pH of the mixture is adjusted to 7-8 by addition of saturated Na2HPO4 solution. A solution of RuCl3 (9.9 mg, 0.05 mmol) in water (0.5 mL) is added and the reaction mixture is stirred for 2 h, keeping the pH between 6 and 9 by addition of Na2HPO4 solution. Water (100 mL) is added and the pH is adjusted to 6 by addition of 2M HCl solution. EtOAc is added and the organic layer is separated, washed with NaHCO3 and brine. The combined aqueous layers are back extracted once with EtOAc. The combined organic phases are dried (MgSO4) and concentrated to afford the crude compound which is purified by flash column chromatography using EtOAc in hexanes affords the title compound (1.13 g, 47%).
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