[S:1]1[C:5]([C:6]([O:8]CC)=[O:7])=[CH:4][C:3]2[CH:11]3[CH2:15][CH:14]([C:2]1=2)[CH2:13][CH2:12]3.C(O)C.[OH-].[Li+].Cl>O.C1COCC1>[S:1]1[C:5]([C:6]([OH:8])=[O:7])=[CH:4][C:3]2[CH:11]3[CH2:15][CH:14]([C:2]1=2)[CH2:13][CH2:12]3
A 100-mL single-neck round bottomed flask equipped with a magnetic stirrer and reflux condenser was purged with nitrogen and charged with 1d (930 mg, 4.19 mmol), ethanol (7 mL), THF (7 mL), water (7 mL) and lithium hydroxide (301 mg, 12.6 mmol) and the mixture heated at 50° C. for 4 h. After this time, the reaction was cooled to room temperature and acidified to pH 1.5 with 2N hydrochloric acid. The resulting precipitate was collected by vacuum filtration, washed with water (2×10 mL) and dried overnight under vacuum to afford a 94% yield (768 mg) of 1e as a white solid: mp 183-184° C.; 1H NMR (500 MHz, DMSO-d6) δ 12.66 (br s, 1H), 7.48 (s, 1H), 3.59 (m, 1H), 3.41 (m, 1H), 1.97-1.83 (m, 3H), 1.61 (dt, 1H, J=9.0, 2.5 Hz), 0.96 (dd, 2H, J=12.5, 3.5 Hz); MS (APCI−) m/z 193.2 (M−H).
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