SYNTHESIS AND ABSOLUTE-CONFIGURATION OF (-)-METHYL (E)-2,4,5-TETRADECATRIENOATE, SEX ATTRACTANT OF MALE DRIED BEAN WEEVIL

(-)-Methyl (E)-2,4,5-tetradecatrienoate [(-)-1, [α]D-98°] was synthesized from β-cyanopropionaldehyde dimethyl acetal. The key intermediates, (R,R)- and (S,R)-1-ethynyl-3-carbomethoxypropyl N-[1-(1-naphthyl)ethyl]-carbamates (4a,b) are separable using liquid chromatography. The low temperature reaction of 4b with lithium di-n-octylcuprate affords (R)-(-)-methyl 4,5-tetradecadienoate [R-(-)-5] and this allene was then converted to (R)-(-)-1. Similarly, (S)-(+)-1 is prepared from 4a. The synthetic pheromone, (R)-(-)-1, has 77% the rotatory power of the natural product. © 1978, American Chemical Society. All rights reserved.