Asymmetric synthesis of unsaturated α-benzyloxyaldehydes: an enantioselective synthesis of (+)-exo-brevicomin

Enantioselective synthesis of α-hydroxy aldehydes with an alkene tether was accomplished from l-(+)-tartaric acid, employing stereoselective reduction of a 1,4-diketone with L-selectride as the key step. Synthetic utility of these aldehydes was demonstrated in the synthesis of pine beetle pheromone (+)-exo-brevicomin.