The Four Isomeric 1,3,5‐Undecatrienes. Synthesis and configurational assignment

Abstract

The four geometrical isomers of 1,3,5-undecatriene, l a 4 have been prepared (stereospecifically and non-stereospecifically), using either (1) the Wittig reaction, (2) thermal sigmatropic hydrogen shifts, (3) partial reduction of triple bonds by zinc, or (4) organocopper reagents. The thermal behaviour of the four 1,3,5-undecatrienes has been investigated and the products formed have been characterized. The spectra of la-d, and of related compounds, have been discussed in order to corroborate their configurational assignment. 1. Introduction. -Some 1,3,5-undecatrienes isolated from the essential oils of both 4. 58; d x d; J = 16; J ' = 7 4. 58; d; J = 7 2.8; d x d; J = 21; J'=12 2. a; d; J = 21 2 . 8 ; d; J = 12 4 . 6 3 ; d x d; J = 15; J ' = 7 4. 63; d; J = 7 5. 58; 12-line system 5. 58; d x t; J = 15; J' = 7 5. 56; d x d; J = 15; J ' = 6 5. 56; d; J = l! 5.33; dxdxt; J = 15; J ' = 6; J I I = 7 5. 33; d x t; J = 1 5 ; J 1 = 7 5.42; d x d; J = 14; J ' = 11 5. 42; d x d; 5.14; J ' = U 5.42; d x d; J = 14; J'= 11 5.96; dxdxt; 5=15; J ' = 6; J I I = 7 5. 96; d x t; J = 15; J ' = 7 5. 07; d with fine splitting; J = 8 / 5.1; d with fine splitting; J = 17 4. 03; d x d; J 10; J' = 2/ 4. 29; d x d; J = 17; J' = 2 4. 03; d; J = 2/ 4. 29; d; J = 2 4.03; d x d ; J = 10; J'= 21 4.29; d x d ; J = 17; J ' = 2Summary. I n the adult male cecropia moth, l-[14C]-propionate is incorporated specifically into juvenile hormone I (1). By chemical degradation it was found that only C(7) and C(11) are labelled, each carbon atom bearing 50% of the radioactivity originally present in J H -I . It is concluded that propionate serves as a precursor of homomevalonate, which in turn is a precursor for J H -I . Application of 2-[W]-propionate and 3-[14C]-propionate leads to extensive randomization of the label. Apparently propionate is metabolized such that C(2) and C(3) can be reused as smaller fragments-probably acetate-while C(l) is either highly diluted or removed from the propionate in a metabolically inactive form.The insect juvenile hormones I and I1 ( J H -I , 1; JH-11, 2 ) are the only known terpenoid compounds where methyl groups biosynthetically derived from C(3') of mevalonate are formally replaced by ethyl groups. They were discovered in adult males of the saturniid moth Hyalophora cecropia [l] [Z] and were also isolated from the related species Hyalophora gloveri [3] and Samia Cynthia [4]. Juvenile hormone is produced by corpora allata, a pair of glands associated with the insect brain. It was *

Aroma Character Impact Compounds in Kinokuni Mandarin Orange (Citrus kinokuni) Compared with Satsuma Mandarin Orange (Citrus unshiu)

“…The following compounds were purchased from commercial sources: hexanal, (Z)-hex-3-enal, 1,8-cineole, octanal, (Z)-hex-3-en-1-ol, nonanal, 2-isopropyl-3-methoxypyrazine, acetic acid, citronellal, decanal, (E)-non-2-enal, linalool, undecanal, (E)-dec-2-enal, dodecanal, (E)-undec-2-enal, citronellol, perillaldehyde, (2E,4E)-deca-2,4-dienal, geraniol, (E)-dodec-2-enal, eugenol, thymol, isothymol, indole, -pinene, myrcene, limonene, -terpinene, isoamyl alcohol, oct-1-en-3-one, (E)-hept-2-enal, (E)-oct-2-enal, benzaldehyde, (2E,6Z)-nona-2,6-dienal, 2-methylbutanoic acid, 2-acetyl-2-thiazoline, 2-phenylethanol, 4-hydroxy-2,5-dimethylfuran-3(2H)-one, methyl Nmethylanthranilate and vanillin (Sigma-Aldrich Japan, Tokyo, Japan); -damascenone (Firmenich, Meyrin, Switzerland); a mixture of 2-ethyl-4-hydroxy-5-methylfuran-3(2H)-one and 5-ethyl-4-hydroxy-2-methylfuran-3(2H)-one (Givaudan, Vernier, Switzerland); and tridec-1-ene (Tokyo Chemical Industry Co., Tokyo, Japan). The following compounds were synthesized by the methods reported in the literature: (3E,5Z)-undeca-1,3,5-triene, 26) (3E,5Z,8Z)-undeca-1,3,5,8-tetraene, 27) 6-methylheptanal, 28) 6-methyloctanal, 28) yuzunone ((6Z,8E)-undeca-6,8,10-trien-3-one), 29) yuzuol ((6Z,8E)-undeca-6,8,10-trien-4-ol), 30) (2E)-cis-4,5-epoxydec-2-enal, 31) (2E)-trans-4,5-epoxydec-2-enal, 32) (2E,7Z)-trans-4,5-epoxydeca-2,7-dienal 33) and wine lactone (3,6-dimethyl-3a,4,5,7a-tetrahydro-1-benzofuran-2(3H)-one). 34,35) All reagents and solvents were of analytical grade.…”

Toward a Synthesis of Hirsutellone B by the Concept of Double Cyclization

“…We proposed that the desired aryl ether bond could be formed via a palladium-catalyzed Tsuji–Trost reaction with phenol 14 . 17 Our design also makes use of the Wittig reaction to form two key carbon-carbon bonds, utilizing phosphonium salt 13 18 and the known phosphorane 15 . 19 In both cases, the use of a stabilized or semi-stabilized phosphorus ylide would establish the desired trans olefin geometry.…”

Bridging the Final Gap in Stereocontrolled Wittig Reactions: Methoxymethoxy-Armed Allylic Phosphorus Ylides Affording Conjugated Dienes with Highcis Selectivity

“…The preparation of (3Z,5E)-1,3,5-undecatriene [49,50] (4 a, aldehyde R'' H 9 C 4 ), a stereoisomer of galbanum constituents [49] and of a brown betaine ± ylide epimerization [2,3,5] moderated Cl, Br, I, OCH 3 methoxymethoxy-armed ylides [47] no need! (see text) moderated 2-alkenyl methoxymethoxy-armed ylides: present work alkyl P ylides; [38,39] PO ylides [40,41] moderated (hetero)aryl methoxymethoxy-armed ylides [46] no need!…”