反应详情

21.8 g (0.26 mole) of 3,4-dihydro-2H-pyran was dropwise added at room temperature to a mixture of 29.2 g (0.2 mole) of isobutyl (R)-(+)-lactate and 0.3 g of phosphorus oxychloride. After the completion of the dropwise addition, the resulting mixture was stirred at room temperature for 4 hours. After the reaction, 100 ml of ethyl acetate was added, followed by washing with 70 ml of a saturated aqueous sodium hydrogen carbonate solution, 70 ml of water and 70 ml of a saturated aqueous sodium chloride solution in this order. The washed material was dried over anhydrous sodium sulfate and then subjected to vacuum distillation to remove the solvent, whereby was obtained 49.0 g (yield: 92.1%) of an oily title compound (diastereomixture).

1. additionAfter the completion of the dropwise addition
2. additionwas added
3. washby washing with 70 ml of a saturated aqueous sodium hydrogen carbonate solution, 70 ml of water and 70 ml of a saturated aqueous sodium chloride solution in this order
4. dry with materialThe washed material was dried over anhydrous sodium sulfate
5. distillationsubjected to vacuum distillation
6. customto remove the solvent