反应详情

3,4-Dihydro(2H)pyran (7.22 g, 84.9 mmol) was added dropwise to a solution of 2-bromo-1,4-benzenedimethanol (7.76 g, 35.8 mmol) obtained from Example 1-(1) and p-toluenesulfonic acid monohydrate (340.2 mg, 1.80 mmol) in dichloromethane (180 ml) with stirring at 0° C. The mixture was stirred for 1 hour, and then 3,4-dihydro(2H)pyran (0.8 g, 9.3 mmol) was further added thereto. After the mixture was stirred for 40 minutes, a saturated aqueous solution of sodium hydrogen carbonate (100 ml) was added thereto, then the resulting mixture was stirred for 5 minutes, and the product was extracted with ethyl acetate. The organic layer was washed with a saturated aqueous solution of sodium chloride, and the solvent was distilled off under reduced pressure. The obtained residue was subjected to chromatography on a silica gel (250 g) column (eluent; ethyl acetate:hexane=1:10) to give the title compound (12.07 g, 88% yield) as an oil.

1. stirringAfter the mixture was stirred for 40 minutes
2. stirringthe resulting mixture was stirred for 5 minutes
3. extractionthe product was extracted with ethyl acetate
4. washThe organic layer was washed with a saturated aqueous solution of sodium chloride
5. distillationthe solvent was distilled off under reduced pressure