Methyl iodide → (3S,4R,6R)-4-(3-chlorophenyl)-3-(4-chlorophenyl)-6-methyl-2-(2-propanyl)-1,2-thiazinan

To a degassed solution of 239.9 mg (0.602 mmol) of (3S,4R)-4-(3-chlorophenyl)-3-(4-chlorophenyl)-2-(2-propanyl)-1,2-thiazinan (Example 117, Step D) in THF (2.0 mL) was added iodomethane (60.0 μl, 0.960 mmol), followed by dropwise addition of a 1 M solution of lithium bis(trimethylsilyl)-amide in THF (640.0 μl, 0.640 mmol). After stirring at room temperature for 17 hours, the reaction was quenched with MeOH (3 mL), then concentrated under reduced pressure. Purification by flash chromatography on silica gel (0 to 70% DCM in hexanes gradient) provided the title compound as a white solid. The 1H NMR showed 6% of the 6S epimer was also isolated.