An unprecedented facile oxidation of 1,3,5-trisubstitutedpyrazolines and Hantzsch 1,4-dihydropyridines (DHPs) to the corresponding pyrazoles and pyridines was observed, mediated by 3,4-dihydro-2H-pyran in air. The reaction showed excellent reactivity, functional group tolerance, and high yield without using any metal and/or halogen based oxidizing agents.