Pheromone synthesis, CXXVI. Synthesis and biological activity of four stereoisomers of 6,10,14‐trimethyl‐2‐pentadecanol, the female‐produced sex pheromone of rice moth (Corcyra cephalonica)

The synthesis of four stereoisomers of the female‐produced sex pheromone [(2R,6R,10R)‐, (2S,6R,10R)‐, (2S,6S,10S)‐, and (2R,6S,10S)‐ 1a ] of the rice moth (Corcyra cephalonica) was achieved by starting from (R)‐ 2a , (R)‐ or (S)‐ 3a , and (R)‐ or (S)‐ 4 and using alkylation of alkyl phenyl sulfones as the coupling reaction. Behavioral bioassay of each isomer revealed (2R,6R,10R)‐ 1a to be eight times more active than a diastereomeric mixture of equal amounts of the eight possible stereoisomers, indicating that (2R,6R,10R)‐ 1a is probably the natural pheromone or at least the major component of the female blend. Electrophysiological bioassay also confirmed the high activity of (2R,6R,10R)‐ 1a .