反应详情

2.0 g of the compound obtained in Example 2 was dissolved in 40 mL of dichloromethane, and the resulting solution was cooled to below 5° C. 13.4 g of triphenylphosphine dibromide was added thereto, and the resulting mixture was warmed to room temperature, stirred for 4 hours, and concentrated by evaporation under reduced pressure. To the residue, 5 mL of ethyl acetate and then 15 mL of n-hexane were added. The resulting mixture was stirred for 1 hour at room temperature and 2 hours at below 5° C., filtered and condensed under reduced pressure. The residue was subjected to silica gel column chromatography (eluent, n-hexane:ethyl acetate=10:1) to obtain 2.9 g (yield of 80%) of the title compound as a yellowish oil.

1. temperaturethe resulting solution was cooled to below 5° C
2. concentrationconcentrated by evaporation under reduced pressure
3. additionTo the residue, 5 mL of ethyl acetate and then 15 mL of n-hexane were added
4. stirringThe resulting mixture was stirred for 1 hour at room temperature and 2 hours at below 5° C.
5. filtrationfiltered
6. customcondensed under reduced pressure