Polysubstituted 2, 3-dihydrofuro [2, 3-b] pyridines and 3, 4-dihydro-2H-pyrano [2, 3-b] pyridines have been synthesized from 1, 2, 4-triazines using the inverse electron Diels– Alder reaction. For this purpose, 3-methylsulfanyl-1, 2, 4-triazines were reacted with several nucleophiles allowing the formation of appropriately substituted alkynes to undergo the intramolecular inverse electron demand Diels–Alder reaction. Sealed-tube microwave ...