反应详情

8.4 g (0.204 mole) of sodium borohydride was suspended at room temperature in a solution of 35.8 g (0.17 mole) of the methyl (R)-(+)-2-(1-isobutoxyethoxy)propionate (obtained in Reference Example 5) dissolved in 170 ml of toluene. Thereto was dropwise added slowly 40.8 ml (1.02 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 mixture was stirred at room temperature for 4 hours to give rise to a reaction. To the reaction mixture was added 50 ml of water, followed by stirring for 0.5 hour. The organic layer was separated. The water layer was subjected to re-extraction with 50 ml of toluene. The two organic layers were combined and washed with 50 ml of water and 50 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. The resulting concentrate was subjected to distillation to obtain 28.9 g (yield: 98.0%) of an oily title compound (diastereomixture).

1. customcould be kept at 40° C
2. additionAfter the completion of the dropwise addition
3. stirringthe mixture was stirred at room temperature for 4 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 re-extraction with 50 ml of toluene
9. washwashed with 50 ml of water and 50 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
13. concentrationThe resulting concentrate
14. distillationwas subjected to distillation