[O:1]1[CH2:3][C:2]21[CH2:9][CH:8]1[N:10]([C:11]([O:13][CH2:14][C:15]3[CH:20]=[CH:19][CH:18]=[CH:17][CH:16]=3)=[O:12])[CH:5]([CH2:6][CH2:7]1)[CH2:4]2.C([O-])(O)=O.[Na+].C(OCC)(=O)C>O1CCCC1>[CH:3]([CH:2]1[CH2:4][CH:5]2[N:10]([C:11]([O:13][CH2:14][C:15]3[CH:16]=[CH:17][CH:18]=[CH:19][CH:20]=3)=[O:12])[CH:8]([CH2:7][CH2:6]2)[CH2:9]1)=[O:1]To a cold (0° C.) solution of EXAMPLE 84A (3.5 g) in tetrahydrofuran (40 mL) was added boron trifluoride diethyl ether complex (0.82 mL). The mixture was stirred at 3-5° C. for 3 hours. Aqueous saturated NaHCO3 was added, followed by ethyl acetate (200 mL). The organic layer was separated, washed with water (twice) and concentrated to dryness. Toluene was added and the mixture was concentrated under vacuum to provide the title compound.
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