反应详情

温度

-78 °C

Under a nitrogen atmosphere, 2.64 ml of oxalyl chloride was added to 40 ml of dichloromethane and the mixture was cooled to -78° C. Then, a solution of 3.62 ml of dimethyl sulfoxide in 10 ml of dichloromethane was added dropwise at -78° C. and the mixture was stirred for 30 minutes. A solution of 5.4 g of 5-acetoxy-4,6-di-t-butyl-2-hydroxymethyl-2-methyl-2,3-dihydrobenzofuran synthesized in Example 47 in 15 ml of dichloromethane was added dropwise and the mixture was stirred again at -78° C. for 1 hour. The mixture was combined with 15.3 ml of triethylamine and allowed to warm to room temperature over 1 hour. After reaction, the reaction solution was combined with a saturated aqueous ammonium chloride solution and extracted with ethyl acetate. The organic layer was 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 3.95 g of 5-acetoxy-4,6-di-t-butyl-2-formyl-2-methyl-2,3-dihydrobenzofuran (rotamer mixture) as a white crystal (yield 71%).

1. stirringthe mixture was stirred again at -78° C. for 1 hour
2. temperatureto warm to room temperature over 1 hour
3. customAfter reaction
4. extractionextracted with ethyl acetate
5. dry with materialThe organic layer was dried over anhydrous magnesium sulfate
6. concentrationconcentrated
7. customThe concentrate was purified by silica gel column chromatography
8. washeluting with n-hexane containing 20% ethyl acetate