To a solution of the product of Example 6C (200 mg, 0.546 mmol) dissolved in anhydrous dichloromethane (6.0 mL) was added TsCl (125 mg, 0.656 mmol), DMAP (100 mg, 0.819 mmol) and triethylamine (0.0914 mL, 0.656 mmol). The reaction mixture continued stirring at room temperature. After 22 hours the reaction mixture was diluted with water. The aqueous layer was separated and extracted with ethyl acetate (3×). All combined organic layers were dried over Na2SO4, filtered, and concentrated to provide an oil. The crude material was purified using silica gel:chromatography (70:30 pentane:ethyl acetate) to provide the desired product (166 mg, 0.319 mmol) in 58% yield. 1H (CDCl37.80 (2H, d, 600 MHz): δ J=8.3 Hz), 7.72 (1H, s), 7.32 (2H, d, J=7.9 Hz), 7.29 (2H, d, J=8.7 Hz), 6.74 (2H, d, J=8.7 Hz), 5.22 (2H, s), 4.19 (1H, m), 4.02 (1H, dd, J=10.4, 6.0 Hz), 3.93 (1H, dd, J=10.4, 4.5 Hz), 2.44 (3H, s), 1.63 (9H, s) 1.42 (3H, d, J=6.5 Hz); 13C (CDCl3 158.9, 150 MHz): δ 158.3, 153.6, 144.6, 133.8, 129.6, 128.8, 127.8, 127.4, 125.1, 118.0, 114.7, 76.8, 71.5, 69.7, 66.2, 27.7, 21.5, 17.6.; HRMS calcd for C25H29ClN2O6S: 521.150762, found 521.1505.
