Synthesis of the Pheromones, (E)-3, 7-Dimethyl-2, 7-Octadienyl Propionate, (E)-3, 7-Dimethyl-2-Octene-1, 8-Diol and Frontalin from a Common Intermediate1

Ketal ester 9 has been prepared in five steps from methyl levulinate 4 (scheme 1). The propionate 1, diol 2 and (±) frontalin 3 were prepared from ester 9 employing the routes shown in scheme 2,3 and 4 respectively. The branched chain alkenes 13 and 20 were prepared conveniently from the primary alcohols 11 and 10 following the procedure of S.Wolff. Triethyl phosphonopropionate 7 has been prepared by methylating triethylphosphonoacetate with methyl iodide in the presence of sodium hydride.