The reaction of selenoaldehydes with 2-methoxyfuran using their generation by retro Diels–Alder reaction

Selenoaldehydes, regenerated by thermal retro Diels–Alder reaction of anthracene cycloadducts under neutral conditions, reacted with 2-methoxyfuran to give methyl penta-2,4-dienoates along with the deposition of elemental selenium. In a similar reaction with 2-methoxyfuran using thioaldehyde, thiirane compound was isolated. This suggests the formation of selenirane intermediates in the above reaction.