Furan-site transformations of obacunone as potent insecticidal agents

摘要

Furan ring is a key pharmacophore for insecticidal activity of limoninoids. To develop natural-product-based insecticidal agents, a series of furan-site transformations (>2, >3 and >3a–>j) of obacunone were synthesized by selective bromination and following coupling reactions without altering other functional groups. Bioassays indicated that derivatives >3e, 3f and >3j displayed more potent insecticidal activity than obacunone and toosendanin against the instar larvae of Mythimna separate Walker. Besides, their structure–activity relationships were discussed.