INSECT PHEROMONES AND THEIR ANALOGUES. XVIII. REGIOSPECIFIC SYNTHESIS OF (+/-)-15,19-DIMETHYLTRITRIACONTANE - A COMPONENT OF THE PHEROMONE OF Stomoxys calcitrans

Article abstract of DOI:10.1007/BF00597815

(+/-)-15,19-Dimethyltritriacontane (II) - a component of the pheromone of the stable fly - has been obtained by a five-stage synthesis from dimethylcyclooctadiene (I).The coupling of 1,1-dimethoxy-4-methyl-8-oxonon-4Z-ene with n-C13H27CH=PPh3 (THF; -30 deg C, 2 h; 25 deg C, 15 h; Ar) gave 1,1-dimethoxy-4,8-dimethyldocosa-4Z,8Z(E)-diene (III).The hydrolysis of (III) (TsOH.Py, H2O-Ac, boiling, 4 h) gave the corresponding aldehyde (IV).The condensation of (IV) with n-C10H21CH=PPh3 (THF; -60 to -30 deg C, 2 h, 25 deg C, 15 h) led to 15,19-dimethyltritriaconta-11Z(E),15Z,19Z(E)-triene (V), the exhaustive hydrogenation of which (ethanol, H2, 5percent Pd/C, 25 deg C) gave (II).The substance, the yield in percent, and R_f values are given, respectively: (II), 95, 0.92; (III), 29, 0.74; (IV), 80, 0.72; (V) 50, 0.8.The IR and PMR spectra of compounds (II)-(V) and the mass spectra of (II) and (III) are given.