Abstract
The optical isomers (R)-(–)- and (S,)-(+)-tetrahydro-4-fluoromethyl-4-hydroxy-2H-pyran-2-one (fluoromevalonolactone,. FMev) of the insect anti-juvenile hormone were synthesized by using combined enzymatic and chemical methods, and their biological activities were examined by using the silkworm Bombyx mori L. It was found that the observed anti-juvenile hormone and insecticidal activity against Bombyx mori after topical treatment with racemic FMev was due to the (R)-(–)-enantiomer of FMev, the (S,)-(+)-enantiomer being inactive.