[C:1](Cl)(=[O:8])[C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=1.[OH:10][C@@:11]1([C:19]([O:21][CH3:22])=[O:20])[CH2:17][C@@H:16]([OH:18])[C@@H:15]2[C@@H:13]([O:14]2)[CH2:12]1.C(N(CC)CC)C>ClCCl>[C:1]([O:18][C@H:16]1[C@@H:15]2[C@@H:13]([O:14]2)[CH2:12][C@:11]([OH:10])([C:19]([O:21][CH3:22])=[O:20])[CH2:17]1)(=[O:8])[C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=1Benzoyl chloride (0.216 mL, 1.86 mmol) was added dropwise to a 0° C. solution of Example 17C (0.35 g, 1.86 mmol) and triethylamine (0.52 mL, 3.74 mmol) in dichloromethane (20 mL). The reaction mixture was stirred overnight at room temperature, washed with saturated NaHCO3 solution, brine, dried (MgSO4), filtered and concentrated. The concentrate was purified by flash column chromatography using hexanes/ethyl acetate (3/2) to afford 495 mg (91%) of the desired product as a colorless oil.
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