An unexpected formation of the novel 7-oxa-2-azabicyclo[2.2.1]hept-5-ene skeleton during the reaction of furfurylamine with maleimides and their bioprospection using a zebrafish embryo model.

An unexpected intramolecular cyclization during the reaction of furfurylamine with maleimides is reported as a novel strategy for the efficient green synthesis of the 7-oxa-2-azabicyclo[2.2.1]hept-5-ene skeleton. Under the same reaction conditions, 7-oxabicyclo[2.2.1]hept-5-enes were synthesized when furfurylamine was N-protected by the acetyl group. Both types of bicycloheptenes were screened using the zebrafish model system for genetics and developmental biology.