Reaction Steps
To a stirred solution of 5G (0.023 g, 0.051 mmol) in 0.3 ML of acetonitrile at room temperature under argon was added iodotrimethylsilane (0.020 mL, 0.144 mmol). The yellow solution was stirred 20 min and then quenched with methanol (2 mL). After stirring for 30 min, the reaction mixture was evaporated and then re-evaporated from dichloromethane/hexanes. The solid residue was slurried twice with ether, decanting each time. The remaining solid was slurried in 10% sodium carbonate solution (1.0 mL) at room temperature while a solution of benzenesulfonyl chloride (0.020 mL, 0.157 mmol) in 1.0 mL of THF was added. After rapid stirring for 15 h, the reaction mixture was diluted with water. The solution was adjusted to pH 8 with a few drops of hydrochloric acid and then extracted twice with EtOAc. The organic extracts were dried (MgSO4), filtered, evaporated and purified by chromatography on silica gel (1:5 Ether/CH2Cl2) to give the title compound as a yellow solid (16.5 mg, 71% yield). MS [M+H]+: found 457. HPLC (Method C): retention time, 7.33 min; 98.3% purity. 1H NMR (CDCl3, 400 MHz) δ7.90 (m, 2H), 7.77 (m, 2H), 7.54 (m, 1H), 7.49-7.37 (m, 5H), 7.32-7.21 (m, 6H), 5.61 (d, 1H, J=8.0 Hz), 5.09 (d, 2H, J=14.9 Hz), 4.59 (d, 2H, J=14.9 Hz), 3.84 (m, 1H), 3.33 (dd, 1H, J=2.6, 11.3 Hz), 3.09 (m, 1H), 2.90 (dd, 2H, J=4.4, 17.1 Hz), 2.77 (dd, 2H, J=3.1, 17.1 Hz); 13C NMR (CDCl3, 101 MHz) δ155.5, 151.2, 140.7, 137.3, 136.3, 132.7, 129.2, 128.8, 128.7, 128.3, 127.6, 126.9, 125.9, 125.9, 124.9, 51.3, 51.0, 44.8, 33.6.
