We don't have synonyms for pentanes yet — it may be a rare, specialized, newly coined, or misspelled word. The closest thesaurus entries we have are pentane, penates and pennants.
(n) :
(organic chemistry) An aliphatic hydrocarbon of chemical formula C₅H₁₂; either of the three isomers n-pentane, methylbutane (isopentane), and dimethylpropane (neopentane); volatile liquids under normal conditions.
(n) :
(organic chemistry) An aliphatic hydrocarbon of chemical formula C₅H₁₂; either of the three isomers n-pentane, methylbutane (isopentane), and dimethylpropane (neopentane); volatile liquids under normal conditions.