Syntheses and structure–activity relationship of lignans to develop novel pesticides

The syntheses of stereoisomers of butane, butanediol, γ-butyrolactone, tri-substituted tetrahydrofuran (7,9'-epoxy), furofuran, tetra-substituted tetrahydrofuran (7,7'-epoxy and 7,8'-epoxy-8,7'-neolignan), benzylidene, coumarin, indan, and pyran type lignans were achieved. All the stereoisomers of the butane type lignans showed larvicidal activity and anti-phytopathogenic fungal activity. The γ-butyrolactone lignan showed stereospecific cytotoxicity against insect cells. Stereo/enantiospecific plant growth inhibitory activity was observed in tri-substituted tetrahydrofuran, tetra-substituted tetrahydrofuran (7,7'-epoxy), coumarin, and pyran type lignans. The furofuran lignan both inhibited and promoted growth in plants. Stereo/enantiospecific anti-phytopathogenic fungal activity was observed in tetra-substituted tetrahydrofuran (7,7'-epoxy) and <i>E</i>-benzylidene lignans.