4,4,5,5-tetramethyl-2-(2-methylpropyl)-1,3,2-dioxaborolane

反応条件: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

実験手順: 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"

反応条件: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

実験手順: A solution of 50.13 g (0.494 mol) of 2-methylpropylboronic acid in 300 mL of ether, prepared by a procedure substantially similar to the foregoing, was contacted with 112.63 g (0.494 mol) of pinacol hexahydrate and stirred for 24 hours. At the end of this period, the resulting reaction mixture was diluted with 500 mL of hexane. A top layer formed which was separated from the rest of the mixture and contacted with 18 mL of water. After stirring for 15 minutes, 9.52 g of a solid separated, which was removed by filtration. The remaining hexane layer was dried over Na2SO4 and residual solvent was removed by evaporation. The remaining material was then distilled using a 6" spinning band distillation column, to obtain 43.98 g (0.239 mol, 48.4%) of an oil, bp: 65°-72°/13 mm, 1H NMR (90 MHz, CDCl3): δ0.65 (d, J=6.6 Hz, 2), 0.93 (d, J=6.6 Hz, 6), 1.25 (s, 12), 1.86 (hep, J=6.6 Hz, 1); Anal. Calcd. for C10H21O2B: C, 65.25; H, 11.50; B, 5.87; Found: C, 65.07, H, 11.52; B, 6.01. At the end of this period, the resulting reaction mixture A top layer formed which was separated from the rest of the mixture After stirring for 15 minutes 9.52 g of a solid separated which was removed by filtration The remaining hexane layer was dried over Na2SO4 and residual solvent was removed by evaporation The remaining material was then distilled band distillation column

反応条件: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

実験手順: A solution of 50.13 g (0.494 mol) of 2-methylpropylboronic acid in 300 mL of ether, prepared by a procedure substantially similar to the foregoing, was contacted with 112.63 g (0.494 mol) of pinacol hexahydrate and stirred for 24 hours. At the end of this period, the resulting reaction mixture was diluted with 500 mL of hexane. A top layer formed which was separated from the rest of the mixture and contacted with 18 mL of water. After stirring for 15 minutes, 9.52 g of a solid separated, which was removed by filtration. The remaining hexane layer was dried over Na2SO4 and residual solvent was removed by evaporation. The remaining material was then distilled using a 6" spinning band distillation column, to obtain 43.98 g (0.239 mol, 48.4%) of an oil, bp: 65°-72°/13 mm, 1H NMR (90 MHz, CDCl3): δ0.65 (d, J=6.6 Hz, 2), 0.93 (d, J=6.6 Hz, 6), 1.25 (s, 12), 1.86 (hep, J=6.6 Hz, 1); Anal. Calcd. for C10H21O2B: C, 65.25; H, 11.50; B, 5.87; Found: C, 65.07, H, 11.52; B, 6.01. At the end of this period, the resulting reaction mixture A top layer formed which was separated from the rest of the mixture After stirring for 15 minutes 9.52 g of a solid separated which was removed by filtration The remaining hexane layer was dried over Na2SO4 and residual solvent was removed by evaporation The remaining material was then distilled band distillation column

反応条件: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

実験手順: 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"

反応条件: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

実験手順: A solution of 50.13 g (0.494 mol) of 2-methylpropylboronic acid in 300 mL of ether, prepared by a procedure substantially similar to the foregoing, was contacted with 112.63 g (0.494 mol) of pinacol hexahydrate and stirred for 24 hours. At the end of this period, the resulting reaction mixture was diluted with 500 mL of hexane. A top layer formed which was separated from the rest of the mixture and contacted with 18 mL of water. After stirring for 15 minutes, 9.52 g of a solid separated, which was removed by filtration. The remaining hexane layer was dried over Na2SO4 and residual solvent was removed by evaporation. The remaining material was then distilled using a 6" spinning band distillation column, to obtain 43.98 g (0.239 mol, 48.4%) of an oil, bp: 65°-72°/13 mm, 1H NMR (90 MHz, CDCl3): δ0.65 (d, J=6.6 Hz, 2), 0.93 (d, J=6.6 Hz, 6), 1.25 (s, 12), 1.86 (hep, J=6.6 Hz, 1); Anal. Calcd. for C10H21O2B: C, 65.25; H, 11.50; B, 5.87; Found: C, 65.07, H, 11.52; B, 6.01. At the end of this period, the resulting reaction mixture A top layer formed which was separated from the rest of the mixture After stirring for 15 minutes 9.52 g of a solid separated which was removed by filtration The remaining hexane layer was dried over Na2SO4 and residual solvent was removed by evaporation The remaining material was then distilled band distillation column