Reaction Steps
Dess-Martin Periodinane (145 mg, 0.34 mmol) was added to a solution of alcohol from Example 49 (200 mg, 0.285 mmol) in methylene chloride (5 ml) at room temperature. The resulting slurry was stirred at room temperature for 1 h. No starting material was seen by TLC (EtOAc/hexane 2:8). The solid was filtered. The filtrate was concentrated. The residue was purified by flash column on silica gel, eluting with EtOAc/hexane (30:70) to give the title compound as a colorless solid. 1H NMR (CDCl3, 500 MHz): δ a mixture of 6:4 atopoisomers 10.03 (s, 1H), 7.90 (s, ⅖H), 7.89 (s, ⅗H), 7.83 (s, 1H), 7.78 (d, J=8.0 Hz, ⅗H), 7.75 (d, J=8.0 Hz, ⅖H), 7.74 (s, 1.2H), 7.73 (s, 0.8H), 7.72 (s, ⅖H), 7.70 (s, ⅗H), 7.64 (d, J=8.0 Hz, 1H), 7.52 (d, J=8.0 Hz, ⅗H), 7.47 (d, J=8.0 Hz, ⅖H), 7.46 (d, J=8.0 Hz, ⅗H), 7.43 (d, J=8.0 Hz, ⅖H), 7.40 (m, 1H), 7.28 (m, 1.5H), 7.23 (d, J=2.0 Hz, 0.5H), 5.64 (d, J=8.0 Hz, 1H), 5.04 (d, J=15.5 Hz, ⅗H), 4.83 (d, J=16 Hz, ⅖H), 4.09 (d, J=16 Hz, ⅖H), 4.01 (d, J=15.0 Hz, ⅗H), 4.00 (m, ⅖H), 3.91 (m, ⅗H), 2.43 (s, 1.8H), 2.41 (s, 1.2H), 0.65 (d, J=6.5 Hz, 1.8H), 0.61 (d, J=7.0 Hz, 1.2H).
