C[Si]([N-:5][Si](C)(C)C)(C)C.[Li+].Cl[CH:12]([B:16]1[O:20][C:19]([CH3:22])([CH3:21])[C:18]([CH3:24])([CH3:23])[O:17]1)[CH2:13][CH2:14][CH3:15].[F:25][C:26]([F:31])([F:30])[C:27]([OH:29])=[O:28]>O1CCCC1>[F:25][C:26]([F:31])([F:30])[C:27]([OH:29])=[O:28].[CH2:13]([CH:12]([B:16]1[O:20][C:19]([CH3:22])([CH3:21])[C:18]([CH3:24])([CH3:23])[O:17]1)[NH2:5])[CH2:14][CH3:15]1.7 ml (1.7 mmol) of 1M lithium bis(trimethylsilyl)amide in tetrahydrofuran were added dropwise to a solution of 0.37 g (1.69 mmol) of 2-[1(RS)-chlorobutyl]-4,4,5,5-tetramethyl-1,3,2-dioxaborolane in 20 ml of tetrahydrofuran under nitrogen at -78° C. The solution was then stirred overnight at room temperature. The solvent was removed by evaporation and the residue was taken up in diethyl ether. Insoluble material was removed by filtration and the filtrate was cooled to 0° C. 0.39 ml (5.1 mmol) of trifluoroacetic acid was added and the solution was stirred at 0° C. for 30 minutes. The solution was evaporated and the residue was co-evaporated with toluene to give 0.62 g of α-(RS)-propyl-4,4,5,5-tetramethyl-1,3,2-dioxaborolane-2-methylamine trifluoroacetate as a brown oil which was used in the next step without further purification.
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