[O:1]1[C:5]2([CH2:10][CH2:9][CH:8]([C:11]3[CH:21]=[CH:20][C:14]([C:15](OCC)=[O:16])=[CH:13][CH:12]=3)[CH2:7][CH2:6]2)[O:4][CH2:3][CH2:2]1.CC(C[AlH]CC(C)C)C.CO>C1COCC1.CCOCC.[Na].C(C(C(C([O-])=O)O)O)([O-])=O.[K+].[K+]>[O:1]1[C:5]2([CH2:6][CH2:7][CH:8]([C:11]3[CH:12]=[CH:13][C:14]([CH2:15][OH:16])=[CH:20][CH:21]=3)[CH2:9][CH2:10]2)[O:4][CH2:3][CH2:2]1To a cooled (−78° C.) solution of the title compound from Example 10 Step B (450 mg, 1.55 mmol) in THF (8 mL) was added DIBAL-H (3.10 mL, 1.50 M in heptane, 4.65 mmol). After 30 min, the reaction mixture was transferred to a 0° C. bath and was held at this temperature for 45 min, whereupon it was quenched by addition of MeOH (0.63 mL, 15.5 mmol). The resulting mixture was diluted with ether and saturated aqueous sodium/potassium tartrate, and the mixture was stirred rapidly until a clear phase separation was achieved. The organic phase was separated, dried over anhydrous sodium sulfate, and concentrated in vacuo. Purification by flash chromatography on silica gel (0 to 30% EtOAc in hexanes, then 30 to 100% EtOAc in hexanes) provided the title compound: LCMS m/z 231.1 [M−OH]+; 1H NMR (500 MHz, CDCl3) δ 7.29 (d, J=7.5 Hz, 2H), 7.24 (d, J=7.5 Hz, 2H), 4.65 (s, 2H), 3.98 (s, 4H), 2.59-2.54 (m, 1H), 1.87-1.66 (m, 8H).
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