Exo- and endohormones. XII. Synthesis of 7(E),9(Z)-Dodecadien-1-yl Acetate, the sex pheromone of european grape vine moth Lobesia botrana, involving phase transfer technique

The synthesis of 7(E), 9(Z)‐dodecadien‐1‐yl acetate using for the olefination steps Wittig and Horner reactions under phase transfer conditions is reported. The 7(E) double bond was prepared by Horner coupling of 7‐tert‐butoxy‐heptanal (1) with 0,0‐diethylphosphonoacetate (2) in a two phase system. Wittig olefination was used to build up the 9(Z) double bond by reacting 9‐tert‐butoxy‐2‐nonen‐1‐yl‐triphenyl‐phosphonium bromide(13) with propionaldehyde under phase transfer catalytic conditions.