Three isomers exist, which differ by the location of the double bond.None of the parent species occur widely, so they are mainly of theoretical interest.Illustrating another isomer of tetrahydropyridine, 6-acetyl-2,3,4,5-tetrahydropyridine occurs naturally.[1][2] A modified Ireland-Claisen rearrangement leads to tetrahydropyridines via a silyl ketene acetal intermediate.[3] Ring-closing olefin metathesis has also been used to establish the tetrahydropyridine ring system.
