[CH:1]([Mg]Br)=[CH2:2].[C:5]([O:13][C@H:14]1[C@@H:20]2[C@@H:18]([O:19]2)[CH2:17][C@:16]([OH:25])([C:21]([O:23][CH3:24])=[O:22])[CH2:15]1)(=[O:12])[C:6]1[CH:11]=[CH:10][CH:9]=[CH:8][CH:7]=1.B(F)(F)F.CCOCC>C1COCC1.[Cu]I>[C:5]([O:13][C@@H:14]1[CH2:15][C@@:16]([OH:25])([C:21]([O:23][CH3:24])=[O:22])[CH2:17][C@@H:18]([CH:1]=[CH2:2])[C@@H:20]1[OH:19])(=[O:12])[C:6]1[CH:11]=[CH:10][CH:9]=[CH:8][CH:7]=1Vinylmagnesium bromide can be added to a −78° C. suspension of CuI in THF. After stirring for 1 hour, a solution of Example 17D and BF3.Et2O in THF can be added. After stirring for 2 hours at −78° C., the reaction mixture can be quenched with saturated NH4Cl. The reaction mixture can be extracted several times with dichloromethane and the combined dichloromethane layers are washed with brine, dried (MgSO4), filtered and concentrated. The concentrate can be purified by flash column chromatography to afford the desired product.
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