Insect Pheromones. Stereoselective Reduction of β- or ω-Alkynols to the Corresponding (E)-Alkenols by Lithium Tetrahydroaluminate

Redn. of RC≡C(CH2)nOH (I; n, R given; 7, MeCHEt(CH2)4; 2, hexyl; 6, Bu; 6, octyl) with LiAlH4 in diglyme-THF gave 85-94% E-RCH:CH(CH2)nOH (II). I (n, R given; 7, MeCHEt(CH2)4; 6, Bu; 6, octyl) were prepd. by reaction of RC≡CLi with the resp. (tetrahydropyranyloxy)iodoalkane. The acetate of II (R = Bu, n = 6) is the sex pheromone of the false codling moth, Argyroploce leucotreta.