Pheromone synthesis, CCVIII: Synthesis of (1S,3S,7R)-3-methyl-alpha-himachalene, the sex pheromone of the sandfly Lutzomyia longipalpis from Jacohina, Brazil

(1S,3S,7R)-3-Methyl-alpha -himachalene, the sex pheromone of the male sandf ly (Lutzomyia longipalpis) from Jacobina, Brazil, was synthesized enantiose lectively by employing Evans' or Oppolzer's asymmetric methylation and intr amolecular Diels-Alder reaction as the two key steps. The absolute configur ation of the product was unambiguously established by X-ray analysis of a c ompound related to one of the synthetic intermediates. The ring junction of this sandfly pheromone possesses the absolute configuration opposite to th at of the known (1R,7R)-alpha -himachalene of plant origin.