3,4-Dehydrorhodopin

1,2-Dihydro-3,4-didehydro-ψ,ψ-carotene-1-ol

3,4-Didehydro-1,2-dihydro-1-hydroxy-ψ,ψ-carotene

1-Hydroxy-3,4-didehydro-1,2-dihydro-ψ,ψ-carotene