3',4'-didehydro-β,β-caroten-4-ol

4'-acetylthio-β,β-carotene

4,4'-diacetoxy-β,β-carotene

rac-(E)-3-(2-iodovinyl)-2,4,4-trimethylcyclohex-2-en-1-ol

15,15'-didehydro-β,β-carotene-4,4'-diol