Retardation effect of jojoba chain length on the chemical reactivity of the liquid wax

Aleksandra Gorodetsky, Inna Zeltser, Arnon Shani

Research output: Contribution to journalArticlepeer-review


Jojoba wax and its derivatives are slow-reacting compounds. To elucidate the reasons for this phenomenon, we reacted jojoba mono- and bis-epoxide and trans-jojoba bis-epoxide (C38-C44 long-chain esters), as well as side chain esters of three steroid skeleton mono-epoxide derivatives with Nal under acidic conditions to yield the corresponding iodohydrins, which then formed the respective bis-keto (or mono-ketone) derivatives. The kinetics, activation energies, and thermodynamic parameters of activation of nucleophilic epoxide opening and pinacol re-arrangement were determined for all these compounds. The reaction rates of the jojoba derivatives were similar to those of two of the epoxides derived from the steroid skeleton compounds, and in the third case the steroid derivative reacted somewhat faster than all the rest. This pattern of rate retardation could stem either from folding of the long jojoba chain, resulting in steric hindrance around the reaction centers, or from repeated unproductive collisions along the long hydrocarbon chain of the jojoba wax (statistical effect). Our results appear to suggest that the multiple unsuccessful collisions were the dominant factor, although steric hindrance cannot be ruled out.

Original languageEnglish
Pages (from-to)373-379
Number of pages7
JournalJAOCS, Journal of the American Oil Chemists' Society
Issue number5
StatePublished - 1 Dec 2005


  • Chemical reactivity
  • Jojoba iodohydrin
  • Jojoba mono- And bis-epoxide
  • Mono- And bis-ketojojoba wax
  • Pinacol rearrangement
  • Retardation
  • Rigid steroid skeleton vs. Flexible long chain

ASJC Scopus subject areas

  • General Chemical Engineering
  • Organic Chemistry


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