反应详情

24 g of the product of Stage A were mixed in 150 ml of toluene and 1.85 g of toluenesulfonic acid were added. The mixture was refluxed for 20 hours. The solvent was evaporated under reduced pressure at 40° C. The residue was chromatographed on silica (eluent: 95/5 hexane/ethyl acetate) to obtain 13.5 g of the expected product.

1. temperatureThe mixture was refluxed for 20 hours
2. customThe solvent was evaporated under reduced pressure at 40° C
3. customThe residue was chromatographed on silica (eluent: 95/5 hexane/ethyl acetate)