Synthesis of acyclic insect pheromones from cycloalkanones via acetylenic lactones

Abstract

De par ta men to de Qu í mi ca, Uni ver si da de de Bra si lia, Bra zil Re ce i ved: Au gust 28, 1996 A Fig. 1 des cre ve um mé to do ge ral para pre pa ra ção de fe ro mô ni os de in se tos. Vá ri os com po nen tes de fe ro mô ni os de in se tos, jun to de seus isô me ros ge o mé tri cos e /ou po si ci o na is, fo ram pre pa ra dos a par tir de Z-lactonas 2a-d , que são fa cil men te aces sí ve is pela hi dro ge na ção es te re os se le ti va (Lind lar Pd, H 2) dos pre cur so res ace ti lê ni cos 1a-d , sen do es tes já sin te ti za dos a par tir de ci clo al ca no nas. A iso me ri za ção de ace ta tos de Z-alqueni las 6a-d aos res pec ti vos es te res de E-alquenilas 8a-d , foi re a li za da tan to pela téc ni ca ca ta lí ti ca (NaNO 2, HNO 3 , ∆) como pelo mé to do de in ver são quí mi ca (NBS, TFA; NaI, DMF, ∆). O ál co ol (E)-6-decenílico ( 7b ) foi tam bém pre pa ra do di re ta men te do es ter ace ti lê ni co ( 15b ) pela re dução, em trans, com hi dre to de lí tio-alumínio (LiAlH 4), por re flu xo em di gli ma. Os ace ta tos de de ci la ( 18 ) e he xa de ci la ( 19 ), com po nen tes dos fe ro mô ni os de ma ri po sa do nabo ( Agro tis se getum ; tur nip moth) e da bor bo le ta Lyco rea ce res ce res, res pec ti va men te, fo ram ob ti dos pela hidro ge na ção ca ta lí ti ca (Pd, H 2) dos ace ta tos de Z-alquenilas cor res pon den tes.Fi gu re 1 des cri bes a ge ne ral met hod for the pre pa ra ti on of in sect phe ro mo nes. Se ve ral mem bers of the ti tle com pounds, along with the ir ge o me tric and/or po si ti o nal i somers, have been pre pa red from Z-lactones 2a-d , which are ea sily ava i la ble from the cor res ponding acety le nic lac to nes 1a-d , pre pa red ear li er from cyclo al ka no nes. The Z to E iso me ri za ti on of al kenyl ace ta tes 6a-d to 8a-d was car ri ed out both by a ca taly tic tech ni que (NaNO 2, HNO 3, ∆) and the che mi cal in ver si on pro ce du re (NBS, TFA; NaI, DMF, ∆). (E)-6-Decenyl al co hol (7b ) was also pre pa red from the acety le nic es ter 15b by the trans re duc ti on with LiAlH 4 in reflu xing digl yme. decyl ace ta te ( 18 ) and he xa decyl ace ta te ( 19 ), phe ro mo ne com po nents of the tur nip moth ( Agro tis se ge tum ) and the male but terfly Lyco rea ce res ce res , res pec ti vely, were ob ta i ned by the ca taly tic hydro ge na ti on (Pd, H 2 ) of the cor res pon ding Z-alkenyl ace ta tes. Key words: in sect phe ro mo nes, Z-lactones, acety le nic lac to nes, cyclo al ka no nesAr ti cle

Synthesis of medium ring and macrocyclic acetylenic lactones by the ring expansion of oxabicycloalkenones

“…The details regarding the conversion of these acetylenic lactones into the corresponding ethylenic compounds, containing either the Z or E double bond, has been reported 10 recently as well as their transformation into the acyclic insect pheromones 25 .…”