We don't have synonyms for octanes yet — it may be a rare, specialized, newly coined, or misspelled word. The closest thesaurus entries we have are octane, octans and octaves.
(n) :
(organic chemistry) Any of the eighteen isomeric aliphatic hydrocarbons (C₈H₁₈) found in petroleum, especially an iso-octane 2,2,4 trimethyl-pentane; they are used as fuels and solvents.
(n) :
(organic chemistry) Any of the eighteen isomeric aliphatic hydrocarbons (C₈H₁₈) found in petroleum, especially an iso-octane 2,2,4 trimethyl-pentane; they are used as fuels and solvents.