Syntheses with sulfones XLIX : stereo- and enantioselective synthesis of (s)-(-)-3,9-dimethyl 6-(1-methylethyl) (e)-5,8-decadien 1-ol acetate, sexual pheromone of yellow scale.

Abstract The stereo- and enantioselective synthesis of the yellow scale pheromone, (S)-(-)-3,9-dimethyl 6-(1-methylethyl) (E)-5,8-decadien 1-ol acetate, from 3-(R) ( +)-valerolactone 5 and [(4-methyl 3-pentenyl) sulfonyl] benzene 8 is described. The key step is the introduction of the isopropyl group by the stereoselective cross-coupling reaction of the dienesulfone 12 with isopropylmagnesium chloride in the presence of FeCl 3 .