反应详情

2.24 g of 5-benzyloxy-2-[3-(4-cyanophenoxy)-3-methyl-1-butenyl]pyridine N-oxide in 45 ml of toluene were heated to 80° C. for 12 hours. The solvent was removed by evaporation and the residue was chromatographed on silica gel using diethyl ether/methanol (97.5:2.5) for the elution to give 0.45 g of 5-benzyloxy-2-(6-cyano-3,4-dihydro-2,2-dimethyl-2H-1-benzopyran-4-yl)pyridine N-oxide in the form of a white solid of melting point 224° C.

1. customThe solvent was removed by evaporation
2. customthe residue was chromatographed on silica gel
3. washfor the elution