反应详情

Under a nitrogen atmosphere, a solution of 4.57 g of 4-hydroxybenzaldehyde in 70 ml of N,N-dimethylformamide was added dropwise to an ice-cooled suspension of 1.5 g of 60% oily sodium hydride in 50 ml of N,N-dimethylformamide and the mixture was stirred at room temperature for 30 minutes. Then, the reaction solution was cooled to 0° C. and a solution of 13.2 g of 5-acetoxy-4,6-di-t-butyl-2-iodomethyl-2-methyl-2,3-dihydrobenzofuran synthesized in Example 70-2) in 100 ml of N,N-dimethylformamide was added dropwise, and the mixture was heated under reflux for 6 hours. After cooling, the reaction solution was combined with a saturated aqueous ammonium chloride solution and extracted with ethyl acetate, and the organic layer was washed with saturated brine, dried over anhydrous magnesium sulfate, and then concentrated. The concentrate was purified by silica gel column chromatography eluting with n-hexane containing 20% ethyl acetate to give 6.4 g of 5-acetoxy-4,6-di-t-butyl-2-(4-formylphenoxymethyl)-2-methyl-2,3-dihydrobenzofuran (rotamer mixture) as a colorless oil (yield 48%).

1. temperaturecooled
2. temperatureThen, the reaction solution was cooled to 0° C.
3. temperaturethe mixture was heated
4. temperatureunder reflux for 6 hours
5. temperatureAfter cooling
6. extractionextracted with ethyl acetate
7. washthe organic layer was washed with saturated brine
8. dry with materialdried over anhydrous magnesium sulfate
9. concentrationconcentrated
10. customThe concentrate was purified by silica gel column chromatography
11. washeluting with n-hexane containing 20% ethyl acetate