Synthesis of potentially bioactive heterocycles: Thermal [3,3]sigmatropic rearrangement of 4-(4 '-aryloxybut-2 '-ynyloxy)-6-methyl-2-pyridone

Synthesis of a number of hitherto unreported 4-aryloxymethylene-7-methyl-2,3-dihydropyrano[3,2-c]pyridine-5-ones 4a-h have been achieved in moderate yields by the thermal [3,3]sigmatropic rearrangement of 4-(4'-aryloxybut-2'-ynyloxy)-6-methyl-2-pyridone.