反应详情

1.85 g of sodium borohydride was suspended at room temperature in a solution of 7.52 g of the isobutyl (R)-(+)-2-(1-ethoxyethoxy)propionate (obtained in Reference Example 3) dissolved in 30 ml of chlorobenzene. Thereto was dropwise added slowly 7.3 ml 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 5 hours. to give rise to a reaction. After the reaction, thereto was added 60 ml of water, followed by extraction with 120 ml of ethyl acetate. The water layer was subjected to extraction with 60 ml of ethyl acetate. The two organic layers were combined and washed with a saturated aqueous sodium chloride solution. 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 4.0 g (yield: 90.8%) 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 5 hours
4. customto give rise
5. customto a reaction
6. customAfter the reaction
7. extractionfollowed by extraction with 120 ml of ethyl acetate
8. extractionThe water layer was subjected to extraction with 60 ml of ethyl acetate
9. washwashed with a saturated aqueous sodium chloride solution
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