Reaction Steps
Tert-butyldimethylsilyltrifluoromethane sulfonate (0.46 g, 1.74 mmol, 3.0 eq) was added to a solution of secondary alcohol 16 (0.5 g, 0.58 mmol, 1.0 eq) and 2,6-lutidine (0.25 g, 2.32 mmol, 4.0 eq) in dry DCM (10 mL) at 0° C. under an atmosphere of nitrogen. After 10 minutes, the reaction mixture was allowed to warm to room temperature and stirred for a further 120 mins. The organic phase was then washed successively with water (10 mL), saturated sodium bicarbonate (10 mL) and brine (5 mL), dried over MgSO4, filtered and concentrated under reduced pressure. The residue was purified by flash chromatography (silica gel, 50/50 v/v n-hexane/EtOAc) to afford the product as a white solid (0.320 g, 57%). LC/MS (4.415 min (ES+)), m/z: 976.52 [M+H]+. 1H NMR (400 MHz, CDCl3) δ 8.31 (br s, 1H), 7.48 (d, 2H, J=8.0 Hz), 7.21 (s, 1H), 7.14 (d, 2H, J=8.3 Hz), 6.89 (s, 1H), 6.65 (s, 1H), 6.38 (d, 1H, J=7.3 Hz), 6.25 (d, 1H, J=14.6 Hz), 5.93 (m, 1H), 5.85 (d, 1H, J=8.8 Hz), 5.50 (m, 1H), 5.34 (m, 1H), 5.24 (m, 2H), 5.15 (d, 1H, J=12.5 Hz), 4.86 (d, 1H, J=12.2 Hz), 4.62 (m, 3H), 4.01 (m, 1H), 3.86 (s, 3H), 3.78 (m, 1H), 3.04 (m, 1H), 2.56 (m, 1H), 2.20 (m, 1H), 1.84 (dd, 3H, J=6.6, 0.7 Hz), 1.48 (d, 3H, J=6.8 Hz), 1.20 (m, 3H), 1.05 (d, 9H, J=2.9 Hz), 1.03 (d, 9H, J=2.9 Hz), 0.99 (d, 3H, J=6.8 Hz), 0.95 (d, 3H, J=6.8 Hz), 0.88 (s, 9H), 0.27 (s, 3H), 0.14 (s, 3H).
