Unexpected addition and cycloaddition products from the reaction of 2-Alkenyl-4H-1,3,4-oxadiazines with dienophiles and dienes

Article abstract of DOI:10.1016/0040-4039(93)85101-2

Reaction of 2-Alkenyl-4H-1,3,4-oxadiazines 3 with electron deficient dienophiles gave linear addition products rather than cycloaddition product. When reacted with an electron-deficient diene, cycloaddition occurred across the olefin and not the imine.