反应详情

43.g of the product of Stage A were refluxed for 2 and a half hours in 250 ml of toluene and 3.1 g of toluenesulfonic acid and the reaction mixture was allowed to cool and was chromatographed on silica (eluent: 9/1 hexane/ethyl acetate) to obtain after evaporation of the solvent at 40° C. under 80 mm of Hg, 20 g of the expected product.

1. temperatureto cool
2. customwas chromatographed on silica (eluent: 9/1 hexane/ethyl acetate)
3. customto obtain
4. customafter evaporation of the solvent at 40° C. under 80 mm of Hg, 20 g of the expected product