Reaction Steps
A solution of 83 (0.138 g, 0.319 mmol, 1 equiv) in CH2Cl2 (3 mL) was cooled to 0° C. prior to sequential addition of Et3N (0.222 mL, 1.59 mmol, 5 equiv) and CH3SO2Cl (0.049 mL, 0.637 mmol, 2 equiv). The cooling bath was removed after 5 min and the mixture was stirred at 25° C. for 1 h. The reaction was quenched with the addition of saturated aqueous NaHCO3 (0.5 mL) and the layers were separated. The aqueous portion was extracted with EtOAc (2×5 mL) and the combined organic portions were dried (MgSO4), filtered, and concentrated. Radial chromatography (SiO2, 2 mm plate, 30% EtOAc-hexane) furnished 84 (0.143 g, 0.163 g theoretical, 89%) as a white solid: mp 134-135° C.; 1H NMR 400 MHz, CDCl3) major rotamer δ 8.40 (d, 8.2 Hz, 1H), 8.13 (d, J=8.6 Hz, 1H), 7.60-7.35 (m, 7H), 6.63 (s, 1H), 5.26 (d, J=11.7 Hz, 1H), 5.17 (d, J=11.6 Hz, 1H), 4.49-4.44 (m, 2H), 4.38-4.30 (m, 2H), 2.69-2.64 (m, 4H), 2.26-2.05 (m, 2H), 1.73-1.70 (m, 2H), 1.32 (s, 9H); 13C NMR (100 MHz, CDCl3) major rotamer δ 153.8, 153.6, 140.5, 136.7, 133.0, 128.8 (2C), 128.6, 128.1 (2C), 127.7, 127.6, 127.1, 125.2, 123.3, 122.8, 107.1, 80.8, 71.4, 70.2, 47.7, 37.1, 36.1, 28.3 (3C), 26.5, 24.4; IR (film) νmax 3056, 2974, 2933, 2862, 1692, 1615, 1590 cm−1; FABHRMS (NBA-NaI) m/z 534.1914 (M+Na+, C28H33NO6S requires 534.1926).
