We don't have synonyms for lactucone yet — it may be a rare, specialized, newly coined, or misspelled word. The closest thesaurus entries we have are lactone, lactulose and lactucin.
(n) :
(organic chemistry) A white, crystalline, tasteless substance found in the milky sap of species of Lactuca, and constituting an essential ingredient of lactucarium.
(n) :
(organic chemistry) A white, crystalline, tasteless substance found in the milky sap of species of Lactuca, and constituting an essential ingredient of lactucarium.