Fission of 2: 3-Dihydropyran into Acrolein and Ethylene

Abstract

IT has been suggested¹ that 2:3-dihydrbfuran (I) on heating above 400° rearranges into cyclopropane aldehyde (II). By analogy, 2: 3-dihydropyran (III) should give cyclobutane aldehyde (IV). Experiments have shown, however, that, on heating, dihydropyran does not produce this aldehyde but splits by homogeneous reaction into acrolein and ethylene (V)². Whether the cyclic aldehyde intervenes in the reaction or not must still remain an open question.