Reaction Steps
To a solution of Intermediate 167b (0.22 mmol) in THF (2.5 mL) was added piperidine (424 μL, 4.3 mmol) and the reaction stirred at 50° C. for 24 h. The crude reaction mixture was cooled and partitioned between EtOAc and water. The aqueous phase was extracted with EtOAc (×3) and the combined organic layers were washed with brine, dried (MgSO4) and concentrated in vacuo. The resultant residue was purified by FCC on silica, using a gradient of 0-10% (2M NH3 in MeOH) in DCM, followed by MDAP (Method 7) purification, to give the title compound (44 mg, 25%). LCMS (Method 5): Rt 3.69 min, m/z 716 [MH+]. 1H NMR (400 MHz, d6-DMSO): 0.86 (3H, d, J=6.2 Hz), 1.23 (9H, s), 1.28-1.33 (2H, m), 1.38-1.48 (6H, m), 1.58-1.66 (2H, m), 1.70-1.92 (4H, m), 1.95-2.12 (2H, m), 2.26-2.34 (4H, m), 2.86 (1H, ddd, J=12.7, 9.0, 3.9 Hz), 3.11 (1H, dt, J=11.9, 4.1 Hz), 3.23-3.29 (1H, m), 3.44 (2H, s), 4.77 (1H, td, J=8.4, 5.7 Hz), 5.46 (1H, t, J=4.2 Hz), 6.28 (1H, s), 6.99 (1H, d, J=8.6 Hz), 7.15 (1H, dd, J=9.8, 2.1 Hz), 7.20-7.25 (2H, m), 7.25-7.29 (2H, m), 7.29-7.36 (3H, m), 7.39 (1H, t, J=7.8 Hz), 7.59 (1H, d, J=10.0 Hz), 7.64 (1H, d, J=1.8 Hz), 8.06 (1H, s), 8.12 (1.8H, s).
