Reaction Steps
A solution of Intermediate 61g (18 mg, 0.02 mmol) in THF (0.10 mL) was treated with tetrabutylammonium fluoride (1M in THF, 0.10 mL, 0.10 mmol) and the mixture was heated to 50° C. for 2 h. The mixture was diluted with DCM and a saturated aqueous sodium bicarbonate solution. The layers were separated and the aqueous layer was then extracted with DCM (2×). The combined organic layers were washed with brine, dried (Na2SO4), filtered and evaporated in vacuo. The residue was purified by HPLC (Method 6; 5-95% MeCN in H2O, 0.1% HCO2H over 25 mins) to give the title compound (5 mg, 33%). LCMS (Method 5): Rt 3.52 min, m/z 747.6 [MH+]. 1H NMR (400 MHz, d6-DMSO): 0.91 (3H, d, J=6.4 Hz), 1.26 (9H, s), 1.44-1.56 (2H, m), 1.61-1.73 (2H, m), 1.74-1.98 (4H, m), 1.99-2.12 (2H, m), 2.13 (3H, s), 2.25-2.37 (3H, m), 2.37-2.49 (5H, m, obscured by DMSO), 2.86-2.95 (1H, m), 3.12-3.19 (1H, m, obscured by water), 3.20-3.44 (1H obscured by water), 3.64 (2H, s), 4.77-4.86 (1H, m), 5.51 (1H, t, J=4.4 Hz), 6.28 (1H, s), 6.81-6.85 (1H, m), 7.05 (1H, d, J=8.6 Hz), 7.15-7.21 (3H, m), 7.24-7.30 (2H, m), 7.30-7.39 (2H, m), 7.63 (1H, d, J=10.2 Hz), 7.69 (1H, d, J=1.7 Hz), 7.95 (1H, s), 8.36 (0.1H, s).
