Absolute configuration of gomadalactones A, B and C, the components of the contact sex pheromone of Anoplophora malasiaca

Absolute configuration of gomadalactones A (1), B (2) and C (3), the pheromone components of the white-spotted longicorn beetle (Anoplophora malasiaca) was assigned as (1S,4R,5S)-1, (1R,4R,5R)-2 and (1S,4R,5S,8S)-3 by comparing their published CD spectra with those of (1R,5R)-(+)-4,4,8-trimethyl-3-oxabicyclo3.3.0]oct-7-ene-2,6-dione (4) and (1S,5R,8S)-(+)-4,4,8-trimethyl-3-oxabicyclo3.3.0]octane-2,6-dione (5) prepared from (R)-(−)-carvone (6).