反应详情

The compound (T-8) (97.5 g) obtained in the above procedure was dissolved in dried THF (500 ml) and the solution was cooled to −70° C. n-BuLi (241 ml) was added dropwise under an atmosphere of nitrogen, and the stirring was continued at −70° C. for another 2 hours. Then, trimethyl borate (62.4 g) in a dried THF solution was added dropwise slowly at −70° C., and the mixture was warmed up to room temperature. The stirring was continued for another 16 hours. After the completion of the reaction, 2N—HCl (200 ml) was added to the reaction mixture. The mixture was extracted with toluene, and the organic layer was washed with water and brine, and then dried over anhydrous magnesium sulfate. The solution was concentrated under reduced pressure to leave pale brown solids. Recrystallization (heptane:toluene=4:1 by volume) gave the compound (T-9) as colorless powders (54.8 g) in 66% yield.

1. additionwas added dropwise under an atmosphere of nitrogen
2. waitThe stirring was continued for another 16 hours
3. additionwas added to the reaction mixture
4. extractionThe mixture was extracted with toluene
5. washthe organic layer was washed with water and brine
6. dry with materialdried over anhydrous magnesium sulfate
7. concentrationThe solution was concentrated under reduced pressure
8. customto leave pale brown solids
9. customRecrystallization (heptane:toluene=4:1 by volume)