Synthesis and antifungal activity of new bis-γ-lactones analogous to avenaciolide

In a study of the antifungal activity of selected compounds as potentials agrochemicals, we have prepared and characterized by elemental analyses, infrared and NMR spectroscopies three new bis-γ-lactones analogous to avenaciolide, where the octyl group of this natural product was replaced by heptyl, hexyl and pentyl groups. The effects on the mycelia development and conidia germination of Colletotrichum gloesporioides of these compounds and their synthetic precursors were evaluated in vitro. The title compounds were active in the tested conditions, while all the synthetic precursors were inactive. The preparation and characterization of 15 new synthetic intermediates are also described. (author)