Identification and synthesis of new bicyclic acetals from caddisflies (Trichoptera)

As shown by synthesis and enantioselective gas chromatography, males and females of the caddisfly species Potamophylax latipennis and Potamophylax cingulatus produce (1R,3S,5S,7S)-1-ethyl-3,5,7-trimethyl-2,8-dioxabicyclo[3.2.1]octane, while Glyphotaelius pellucidus produces 1,3-diethyl-4,6-dimethyl-2,7-dioxabicyclo[2.2.1]heptane, having either the (1S,3S,4R,6S) or (1R,3R,4S,6S)-configuration. As shown by electrophysiological investigations, the compounds are perceived by the antennae of both sexes.