反应详情

13.62 g (100 mmol) of 4-hydroxyacetophenone and 10.04 ml (110 mmol) of 3,4-dihydro-2H-pyran were suspended in 100 ml of anhydrous methylene chloride. At 0° C., 190 mg (1 mmol) of p-toluenesulfonic acid were added with stirring and the mixture was stirred at 0° C. for 3 hours. 10.04 ml (110 mmol) of 3,4-dihydro-2H-pyran were added again and the mixture was stirred at room temperature for a further 3 hours. The batch was poured into 150 ml of water, the phases were separated and the organic phase was extracted with saturated NaHCO3 solution, saturated NaCl solution and with water. The organic phase was dried over sodium sulfate, concentrated and, for purification, chromatographed on silica gel (70-200 μm) using methylene chloride as an eluent. 13.65 g (62%) of 10.1 were obtained.

1. stirringthe mixture was stirred at 0° C. for 3 hours
2. stirringthe mixture was stirred at room temperature for a further 3 hours
3. customthe phases were separated
4. extractionthe organic phase was extracted with saturated NaHCO3 solution, saturated NaCl solution and with water
5. dry with materialThe organic phase was dried over sodium sulfate
6. concentrationconcentrated and, for purification
7. customchromatographed on silica gel (70-200 μm)