Synthesis of (+)-trixagol and its enantiomer, the terpenoid side chain of (−)-agelasine E

The naturally occurring γ-cyclogeranylgeraniol called (+)-trixagol has been synthesised for the first time. Trixagol was readily available in five steps from (S)-2,2-dimethyl-6-methylene-1-cyclohexanemethanol. The enantiomer of trixagol, which equates to the terpenoid side chain of the naturally occurring 7,9-dialkylpurinium salt (−)-agelasine E, was prepared from the (R) enantiomer of the cyclohexanemethanol. Both trixagol enantiomers were moderately active against Mycobacterium tuberculosis.