Kazuya Ujihara

Metofluthrin: A Potent New Synthetic Pyrethroid with High Vapor Activity against Mosquitoes

(1R)-trans-Norchrysanthemic acid fluorobenzyl esters are synthesized and their structure-activity relationships are discussed. These esters show outstanding insecticidal activity against mosquitoes. In particular, the 2,3,5,6-tetrafluoro-4-methoxymethylbenzyl analog (metofluthrin) exhibits the highest potency, being approximately forty times as potent as d-allethrin in a mosquito coil formulation when tested against southern house mosquitoes (Culex quinquefasciatus). Metofluthrin also exhibits a significant vapor action at room temperature.

Total synthesis of (+)-Eurylene

Abstract Eurylene 1 , a cytotoxic bicyclic squalenoid isolated from Eurycoma longifola , has been synthesized utilizing the double vanadium(V)-catalyzed oxidation reaction of different bishomoallyl alcohol systems.

Synthesis of all stereoisomers of the norchrysanthemic acid methyl ester

Abstract Syntheses of eight stereoisomers of methyl norchrysanthemate, (1R)‐trans‐(Z)‐isomer and (1R)‐trans‐(E)‐isomer from (1R)‐trans‐chrysanthemic acid, and other six isomers from (+)‐3‐carene, are described.

Recent Advances of Pyrethroids for Household Use

Development of pyrethroids for household use and recent advances in the syntheses of (1R)-trans-chrysanthemic acid, the acid moiety of most of the household pyrethroids, are reviewed. As another important acid moiety, we discovered norchrysanthemic acid to have a significant vapor action at room temperature when esterified with fluorobenzyl alcohols. In particular, 2,3,5,6-tetrafluoro-4-methoxymethylbenzyl (1R)-trans-norchrysanthemate (metofluthrin) exhibits the highest potency in mosquito coil formulations as well as the vapor action at room temperature against various mosquitoes. Structure-activity relationships of norchrysanthemic acid esters and synthetic studies of norchrysanthemic acid are discussed.