反应详情

温度

-78 °C

To a stirred solution of Ia (7.0 g, 50 mmol) in dry THF (25 mL) at −78° C. was added n-BuLi (1.6 M in n-hexane, 62.5 mL, 100 mmol). After being stirred for 1 hour at −78° C., the reaction mixture was warmed to room temperature and stirred for 1 hour at that temperature. Another flask was charged with 2-isopropoxy-4,4,5,5-tetramethyl-1,3,2-dioxaborolane (7.8 mL, 38 mmol) in dry THF (50 mL) under argon atmosphere, and the reaction mixture was cooled to −78° C. The lithium acetylide from the first flask, which was cooled to −78° C., was slowly added to the second by a double-ended needle. The mixture was stirred at −78° C. for 2 hours, after which anhydrous HCl (100 mmol) was added. Then, reaction mixture was warmed to room temperature. After removal of the precipitated LiCl by filtration and removal of solvents under reduced pressure, the residue was purified by distillation (113-115° C./7 mbar) to afford IIIa (5.9 g, 80%) as an oil.

1. temperaturethe reaction mixture was warmed to room temperature
2. stirringstirred for 1 hour at that temperature
3. temperaturethe reaction mixture was cooled to −78° C
4. additionwas slowly added to the second by a double-ended needle
5. stirringThe mixture was stirred at −78° C. for 2 hours
6. customThen, reaction mixture
7. temperaturewas warmed to room temperature
8. customAfter removal of the precipitated LiCl
9. filtrationby filtration and removal of solvents under reduced pressure
10. distillationthe residue was purified by distillation (113-115° C./7 mbar)
11. customto afford IIIa (5.9 g, 80%) as an oil