Synthesis of 4H,6H-Furo[3,4-c]isoxazole Derivatives as New Potent Fungicides and Their Structure Activity Relationship

Abstract

4H,6H-Furo[3,4-c]isoxazoles (I-IV), potential fungicides, have been designed and synthesized via intramolecular [2+3] cycloaddition of nitroalkyne 3 as a key step. The broad spectrum of fungicidal activities of furoisoxazoles (I-IV) were observed on plant pathogens at 250 ppm. Furoisoxazoles II, III with chlorophenyl at 6-position and methyl or alkylated oxime group at 3-position gave effective control of plant diseases. The furoisoxazole IV with a chlorophenyl group at 4-position also resulted in high fungicidal activities.