New and Simple Syntheses of the Attractants of the Female Melon Fly, Dacus cucurbitae

Abstract

The attractant of the female melon fly, (E)-6-nonenyl acetate, and the two analogs, (E)-7-dodecenyl acetate and (E)-7-decenyl acetate were synthesized via hydrozirconation to control the regioselective coupling reactions and resulted in good yields.(7)8 in 98% yield, by treatment with 2,3-dihydropyran and lithium acetylide-ethylenediamine complex in dimethyl sulfoxide (DMSO). Hydrozirconation" of alkynes 6 and 7 with (CsHshZr(H)CI and h, gave (E)-7-iodo-l-(2-tetrahydropyranyloxyj-o-heptene (8) in 74% yield and (E)-8-iodo-1-(2-tetrabydropyranyloxy).7-octene (9) in 71% yield. The iodides 8 and 9 were then coupled with either ethylmagnesium bromide or butylmagnesium bromide in the presence of tetrakis(triphenylphosphine)-palladium lPd(PPb3)4] as a catalyst to give (E)-1-(2-tetrahydropyranyloxy)-6-nonene (10),10 in 71 % yield, (E)-1-(2-tetrahydropyranyloxy)-7-decene nn" and (E)-1-(2-tetrahydropyranyloxy)-7-dodecene