To a magnetically stirred solution of 0.273 g (0.50 mmol) of the product of Example 182 in 5 mL MeOH was added 0.343 g (0.248 mmol) of potassium carbonate and 0.5 mL water. The reaction mixture was stirred at 60° C. for 3 h then cooled to room temperature and partitioned between EtOAc and 10% aq. NaHSO4. The organic extracts were separated, washed with water and brine, dried (Na2SO4), filtered and evaporated. The residue was purified on a silica gel flash chromatography column eluted with 0–20% EtOAc-hexane. Evaporation of the purified fractions and drying in vacuo afforded the titled compound. HPLC/MS: 453.9 (M+1), 455.8 (M+3); Rt=4.15 min.
