Reaction Steps
To a solution of compound 9D (4.0 g, 7.02 mmol) and cyclopropanecarboxylic acid (10D, (0.91 g, 10.53 mmol) in anhydrous CH2Cl2 (100 mL) was added DIPC (1.63 mL, 10.53 mmol). The reaction mixture was stirred at rt overnight. It was filtered to remove diisopropylurea. The filtrate was purified with silica column chromatography eluting with dichloromethane/EtOAc (v/v 1/1, 7/1, 4/1) to give the title compound (11D, 3.4 g, crude), which was recrystallized from hexanes/acetone to provide pure compound 11D (2.2 g) as white powder in 49% yield. 1H NMR (CDCl3, 500 MHz) δ 10.68 (s, 1H), 8.75 (s, 1H), 8.71 (s, 1H), 7.90 (d, 2H, J=8.5 Hz), 7.63 (s, 1H), 7.56 (d, 2H, J=9.0 Hz), 7.50 (m, 2H), 7.45 (m, 3H), 7.20 (dd, 1H, J=8.5, 2.5 Hz), 6.97 (d, 1H, J=9.0 Hz), 6.57 (s, 1H), 5.69 (d, 1H, J=5.5 Hz), 5.23 (s, 1H), 4.82 (d, 1H, J=12.0 Hz), 3.97 (s, 3H), 3.81 (d, 1H, J=11.5 Hz), 3.72 (d, 1H, J=12.5 Hz), 3.64 (t, 1H, J=12.0 Hz), 3.43 (dd, 1H, J=11.0, 3.0 Hz), 3.11 (t, 1H, J=11.5 Hz), 1.49 (m, 1H), 1.00 (m, 2H), 0.84 (m, 2H). LCMS (ESI) m/z 669.43 (MNa+), 638.39 (MH+), 437.28. HPLC: tR=4.98 min.
