2-(1-chloro-3-methylbutyl)-4,4,5,5-tetramethyl-1,3,2-dioxaborolane

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: 134 mL n-butyllithium (1.6 M, 0.221 mol) were added to 31.08 mL (22.43 g, 0.221 mol) ice-cold diisopropylamine containing 3 mL tetrahydrofuran. The resulting thick liquid was added to a solution of 33.98 g (0.185 mol) 4,4,5,5-tetramethyl-2-(2-methylpropyl)-1,3,2-dioxaborolane (2) in 165 mL glyme containing 17.72 mL (23.5 g, 0.277 mol) methylene chloride at -72°. When this addition was complete, the reaction mixture was stirred for 2 hours, diluted with 165 mL methylene chloride, and a white precipitate removed by filtration. The residue was washed twice with 25 mL portions of methylene chloride. The filtrates were combined, concentrated under reduced pressure, and then distilled from a 12" spinning band column, providing 16.96 g (0.087 mol, 39.46%) of an oil, bp 90°-93°/2.0 mm; 1H NMR (90 MHz, CDCl3): δ0.90 (d, d, J=6, 3 Hz, 6), 1.3 (s, 12), 1.73 (m, 3), 3.45 (d, d, J=6 Hz, 1); Anal. Calcd. for C11H22O2ClB: C, 56.81; H, 9.53; Cl, 15.24; B, 4.65; Found: C, 56.81; H, 9.46; Cl, 15.37; B, 4.53. When this addition a white precipitate removed by filtration The residue was washed twice with 25 mL portions of methylene chloride concentrated under reduced pressure distilled from a 12"

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: 134 mL n-butyllithium (1.6 M, 0.221 mol) were added to 31.08 mL (22.43 g, 0.221 mol) ice-cold diisopropylamine containing 3 mL tetrahydrofuran. The resulting thick liquid was added to a solution of 33.98 g (0.185 mol) 4,4,5,5-tetramethyl-2-(2-methylpropyl)-1,3,2-dioxaborolane (2) in 165 mL glyme containing 17.72 mL (23.5 g, 0.277 mol) methylene chloride at -72°. When this addition was complete, the reaction mixture was stirred for 2 hours, diluted with 165 mL methylene chloride, and a white precipitate removed by filtration. The residue was washed twice with 25 mL portions of methylene chloride. The filtrates were combined, concentrated under reduced pressure, and then distilled from a 12" spinning band column, providing 16.96 g (0.087 mol, 39.46%) of an oil, bp 90°-93°/2.0 mm; 1H NMR (90 MHz, CDCl3): δ0.90 (d, d, J=6, 3 Hz, 6), 1.3 (s, 12), 1.73 (m, 3), 3.45 (d, d, J=6 Hz, 1); Anal. Calcd. for C11H22O2ClB: C, 56.81; H, 9.53; Cl, 15.24; B, 4.65; Found: C, 56.81; H, 9.46; Cl, 15.37; B, 4.53. When this addition a white precipitate removed by filtration The residue was washed twice with 25 mL portions of methylene chloride concentrated under reduced pressure distilled from a 12"