Synthesis and Antifungal Activity of Dispiro-1,2,4-Trioxolane Derivatives

Ten substituted dispiro-1,2,4-trioxolane derivatives were synthesised and screened for antifungal activity in vitro against Rhizoctonia bataticola (Taub) Butler and Sclerotium rolfsii (Sacc.). Dispiro[cyclohexane-1,3’[1,2,4]trioxolane-5’,2"-tricyclo [3.3.1.1^3,7] decan]-4-yl)-N-(3-fluorobenzyl) acetamide (9b) showed maximum activity against S. rolfsii with ED₅₀ 46.90 μg/ml and N-cyclooctyl-2-(dispiro[cyclohexane-1,3’-[1,2,4] trioxolane-5’,2"-tricyclo [3.3.1.1^3,7] decan]-4-yl) acetamide (9g) showed maximum activity against R. bataticola with ED₅₀ 58.23 μg/mL. The antifungal activity of these compounds was less as compared to standard fungicide hexaconazole (ED₅₀ = 13.43 and 18.30 μg/ml against S. rolfsii and R. bataticola respectively).