反应详情

3 g of 2,2-dimethyl-4-(2-pyridyl)-2H-1-benzopyran-6-carbonitrile and 420 mg of sodium tungstate were heated in 30 ml of methanol and 30 ml of acetonitrile at 50° C. and 12 ml of 30% (w/v) hydrogen peroxide were added. After heating overnight the mixture was evaporated and the residue was taken up in dichloromethane and water. The organic phase was separated, dried over sodium sulphate and evaporated. The residue was chromatographed on silica gel using ethyl acetate/petroleum ether (1:3 and 1:2) for the elution to give 440 mg of 1a,7b-dihydro-2,2-dimethyl-7b-(2-pyridyl)-2H-oxireno[c][1]benzopyran-6-carbonitrile which was used without further purification.

1. temperatureAfter heating overnight the mixture
2. customwas evaporated
3. customThe organic phase was separated
4. dry with materialdried over sodium sulphate
5. customevaporated
6. customThe residue was chromatographed on silica gel
7. washfor the elution