Reaction Steps
A solution of Example 153B (20 mg, 0.028 mmol) in methanol (0.28 mL) and water (0.28 mL) was treated with oxone (52 mg, 0.082 mmol) at 25° C. for 1 h. The solvents were evaporated, and the residue was partitioned between ethyl acetate/water, the organic layer was separated, washed with brine, dried over MgSO4, filtered, and the solvents were evaporated. The crude residue was purified by silica gel chromatography eluting with a gradient of dichloromethane, 100% ethyl acetate, to 95% ethyl acetate/5% methanol to give the title compound (9 mg, 43%). 1H NMR (300 MHz, MeOH-D6) δ ppm 0.86(s, 9H), 1.69-1.60(m, 2H), 2.70-2.63(m, 1H), 2.89-2.82(m, 3H), 2.93(s, 3H), 3.3-3.23(m, 1H), 3.45-3.39(m, 1H), 3.53(s, 3H), 3.67(s, 3H), 3.77-3.73(t, J=6.62 Hz, 1H), 3.81(s, 1H), 4.27-4.22(m, 1H), 4.33(m, 1H), 4.63-4.59(dd, J=8.09, 4.78 Hz, 1H), 7.19-7.12(m, 1H), 7.24-7.23(d, J=4.41 Hz, 4H), 7.30-7.27(d, J=8.09 Hz, 2H), 7.35-7.30(m, 1H), 7.80-7.78(d, J=8.09 Hz, 2H), 7.82(m, 1H), 7.87-7.84(dd, J=6.99, 1.84 Hz, 1H), 8.58-8.57(d, J=4.04 Hz, 1H).
