反应详情

To 800 mL of anhydrous tetrahydrofuran, 31.0 g of sodium boron hydride and 71.3 g of lithium bromide were added, and then 10.6 mL of trimethyl borate was added thereto dropwise at 0° C. The resulting mixture was stirred at room temperature for 30 minutes, and then a solution obtained by dissolving 70.4 g of the compound obtained in Example 1 in 200 mL of tetrahydrofuran was slowly added over 2 hours while allowing the resulting mixture to reflux. The reaction solution was further refluxed for 2 hours then cooled to room temperature. 100 mL of anhydrous methanol was added slowly to the solution, and then 700 mL of ethyl ether and 700 mL of water were added. The organic phase was collected, dried over anhydrous magnesium sulfate, and concentrated under reduced pressure to obtain 47.1 g (yield of 90%) of the title compound as an oil.

1. customdropwise at 0° C
2. customa solution obtained
3. additionwas slowly added over 2 hours
4. temperatureto reflux
5. temperatureThe reaction solution was further refluxed for 2 hours
6. temperaturethen cooled to room temperature
7. customThe organic phase was collected
8. dry with materialdried over anhydrous magnesium sulfate
9. concentrationconcentrated under reduced pressure