An improved preparation of some insect sex attractants: Synthesis and separation of geometrical isomers by formation of urea complexes

1979 ◽  
Vol 5 (1) ◽  
pp. 101-108 ◽  
Author(s):  
Graham Leadbetter ◽  
J. R. Plimmer

1961 ◽  
Vol 83 (23) ◽  
pp. 4819-4824 ◽  
Author(s):  
Martin Jacobson ◽  
Morton Beroza ◽  
William A. Jones










1967 ◽  
Vol 10 (6) ◽  
pp. 1190-1191 ◽  
Author(s):  
David. Warthen ◽  
Martin. Jacobson


1977 ◽  
Vol 55 (23) ◽  
pp. 4135-4143 ◽  
Author(s):  
Thomas M. Fyles ◽  
Clifford C. Leznoff ◽  
John Weatherston

A 2% crosslinked divinylbenzene-styrene copolymer, incorporating trityl chloride groups (2) was used in the synthesis of insect sex attractants of Lepidoptera by a two-step alkyne coupling route. Polymer 2 reacted with the symmetrical diols, 1,8-octanediol and1,10-decanediol, to give the monoblocked polymer-bound diols 5 and 6 respectively. Mesylation of 5 and 6 gave the polymer-bound monomesylates 7 and 8 which on coupling with lithioacetylide gave the polymer-bound terminal alkynes 9 and 10 respectively. Acid cleavage of 9 and 10 provide 9-decyn-1-ol and 11-dodecyn-1-ol respectively. A second coupling step was performed by lithiation of 9 and 10 with n-butyllithium or tert-butyllithium followed by treatment with n-butyl bromide or ethyl bromide to give polymer-bound internal alkynes, which on acid hydrolysis gave 9-tetradecyn-1-ol (22), 11-hexadecyn-1-ol (23), and 11-tetradecyn-1-ol (24). If 10 had been lithiated with n-butyllithium and coupled with ethyl bromide, some translithiation occurred to liberate n-butyl bromide which entered into the coupling reaction eventually giving a mixture of 23 and 24. This problem was resolved by the use of tert-butyllithium in the lithiation step. Attempts were made to reduce polymer-bound internal alkynes stereoselectively to cis-alkenes with 9-borabicyclononane, diisobutylaluminum hydride, and catechol borane but all these reagents proved inadequate due to incomplete reduction, overreduction, hydrogenolysis of the alkyne from the polymer, and non-selectivity. Polymer-bound internal alkynes were quantitatively reduced exclusively to cis insect sex attractants using disiamylborane without concurrent overreduction or hydrogenolysis.



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