Asymmetric synthesis of (+)-gomadalactones A and (–)-B: contact sex pheromones of white-spotted longicorn beetle

The white-spotted longicorn beetle (Anoplophora malasiaca), a serious fruit tree pest, relies on contact sex pheromones for mating purposes. The asymmetric synthesis of the pheromonal components, (+)-gomadalactones A and (-)-B, was achieved using an improved enantioselective version of our previous racemic synthesis method. The key 3-oxabicyclo[3.3.0]octane framework was constructed using a combination of Vassilikogiannakis one-pot, photodriven cyclopentenone synthesis with base-mediated lactonization. The enantioselective synthesis was enabled by Sharpless asymmetric dihydroxylation of the starting material, propenylfuran. The route, consisting of 15 steps, is significantly shorter than the previously reported asymmetric synthesis and provides concise and stereochemically reliable access to these biologically important diterpenoid pheromones.