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.