A one-pot synthesis of thiophene and pyrrole derivatives from readily accessible 3,5-dihydro-1,2-dioxines

A one-pot synthesis of 2,5-disubstituted thiophene, 1,2,5-tri- and 2,5-disubstituted pyrrole derivatives from readily available 3,5-dihydro-1,2-dioxines is described. The reaction proceeds by an initial Kornblum–de la Mare rearrangement of the 3,5-dihydro-1,2-dioxine to its isomeric 1,4-diketone followed by condensation of the in situ 1,4-diketone with sulfur, ammonia or a primary amine.