反应详情

1.0 g (0.024 mole) of sodium borohydride was suspended at room temperature in a solution of 5.0 g (0.02 mole) of isobutyl (R)-(+)-2-(1-isobutoxyethoxy)propionate dissolved in 20 ml of toluene. Thereto was dropwise added slowly 7.0 ml (0.12 mole) of methanol with stirring, so that the internal temperature of the reaction system could be kept at 40° C. After the completion of the dropwise addition, the resulting mixture was stirred at 40° C. for 7 hours, at room temperature overnight and at 60° C. for 2 hours to give rise to a reaction. To the reaction mixture was added 20 ml of water, followed by stirring for 0.5 hour. The organic layer was separated. The water layer was subjected to extraction with 20 ml of toluene. The two organic layers were combined and washed with 20 ml of water and 20 ml of a saturated aqueous sodium chloride solution in this order. The washed solution was dried over anhydrous sodium sulfate and then subjected to vacuum distillation to remove the solvent, whereby was obtained 3.0 g (yield: 84.4%) of an oily title compound (diastereomixture).

1. customcould be kept at 40° C
2. additionAfter the completion of the dropwise addition
3. stirringthe resulting mixture was stirred at 40° C. for 7 hours, at room temperature overnight and at 60° C. for 2 hours
4. customto give rise
5. customto a reaction
6. stirringby stirring for 0.5 hour
7. customThe organic layer was separated
8. extractionThe water layer was subjected to extraction with 20 ml of toluene
9. washwashed with 20 ml of water and 20 ml of a saturated aqueous sodium chloride solution in this order
10. dry with materialThe washed solution was dried over anhydrous sodium sulfate
11. distillationsubjected to vacuum distillation
12. customto remove the solvent