Dimethyl-nonatriene

Degenhardt J, Gershenzon J (2000) Demonstration and characterization of ( )-nerolidol synthase from maize a herbivore-inducible terpene synthase participating in (3- )-4, 8-dimethyl-1,3,7-nonatriene biosynthesis. Planta 210 815-822... 

Fig. 2.4. Chromatographic profiles of volatiles emitted by four plant species at different time periods after an attack by Spodoptem littoralis larvae. The labeled peaks are 1, (Z)-3-hexenal 2, ( )-2-hexenal 3, (Z)-3-hexenol 4, (Z)-3-hexenyl acetate 5, linalool 6, ( )-4,8-dimethyl-1,3,7-nonatriene 7, indole 8, ( )-/ -caryophyllene 9, ( ,)-o -bergamotene 10, ( >/3-farnesene 11, ( , )-of-farnesene 12, nerolidol 13, ( , )-4,8,12-trimethyl-1,3,7,11-tridecatetraene 14, of-pinene 15, /3-pinene 16, -myrcene 17, D-limonene 18, ( )-/3-ocimene 19, -sesquiphellandrene 20, germacrene D. Two internal standards, -octane and nonyl acetate, are labeled with IS1 and IS2, respectively.

Fig. 5.1. A sample of floral scent compounds. (1) Substituted methyl esters of benzoic acid. The ester smells unpleasantly sweet when R = H (methyl benzoate), of wintergreen when R = OH (methyl salicylate), and of concord grape when R = NH2 (methyl anthranylate). Odorants with unusual origins and biological functions include the homoterpene 4,8-dimethyl-1,3,7-nonatriene (2) and the wet-earth compound geosmin (3). Some ubiquitous fragrance compounds are ben-zaldehyde (4), benzyl alcohol (5), indole (6), (S)-linalool (7), ( )-/ -ocimene (8), and of-farnesene (9).

Figure 5.1 Examples of terpenoids that are of commercial importance or whose functional role in plants has recently been investigated. Isoprene may stabilize membranes at high temperatures. Camphor, artemisinin and paclitaxel (taxol) are valuable pharmaceuticals. The other three compounds appear to be involved in plant defence pulegone is toxic to herbivores polygodial is a herbivore feeding deterrent and (3 )-4,8-dimethyl-1,3,7-nonatriene, a Cn homoterpene, functions to attract herbivore enemies to herbivore-damaged plants.

The Wittig methylenation of geranial to (E)-4,8-dimethyl-1,3,7-nonatriene is best carried out with phenyllithium in tetrahydrofuran as described in Part... 

Synomones. Semiochemicals that act between organisms of different species and produce advantageous effects both for the sender (producer) and the recipient. S. play an important role in symbiosis. The homo-terpene (3E)-4,8-dimethyl-1,3,7-nonatriene (see ho-moterpenes) is a typical S., it is secreted into the sur-... 

Certain tropical plants create extra protection from hungry arthropods, such as caterpillars, by secreting volatile terpenoids, such as nerolidol and 4,8-dimethyl-1,3,7-nonatriene, in order to attract the herbivore s natural enemies ... 

Hydroxy-9-methoxy-3,7-dimethyl-1 - [2,6,6-trimethyl-cyclohexen-( 1 )-yl ]-nonatrien-(I,4,6)... 

Only few examples have been reported so far on nucleophilic addition reactions to acceptor-substituted polyenes123,124,186 188. In 1933, Farmer and Martin186 examined the reaction of methyl 2,4,6-octatrienoate with sodium dimethyl malonate and isolated the 1,4-adduct as major product (equation 81). In contrast to this, 3,5,7-nonatrien-2-one and ethyl 2,4,6-octatrienoate react with organocuprates under 1,8-addition to provide the 4,6-dien-2-ones and 3,5-dienoates, respectively (equation 82)187. 

Attractive Compounds. The male-produced pheromones of sap beetles, known so far, show the rather stereotypic structures 125-147 (Scheme 15) methyl- and ethyl-branched hydrocarbons with three or four (T)-configured conjugated double bonds [4]. Up to now, 23 compounds could be identified, forming species specific mixtures. Major components in the bouquets are (2E,4E,6E)-5-ethyl-3-methyl-2,4,6-nonatriene, 128, in Carpophilus davidsoni [268] as well as in C.freemani [269], (2 ,4 ,6 )-4,6-dimethyl-2,4,6-nonatriene, 129,in C. truncatus [270], (3 ,5 ,7 )-5-ethyl-methyl-3,5,7-undecatetraene, 132, in C. mutillatus [271],(2 ,4 ,6 ,8 )-3,5,7-trimethyl-2,4,6,8-decatetraene, 134,in C. hemipterus [272] as well as C. brachypterus [273], (2 ,4 ,6 ,8 )-3,5,7-tri-... 

Fig. 11.1 Simplified scheme of the emission and function of herbivore-induced plant volatiles in plant defense. DMNT, 4,8-dimethyl-l,3,7-nonatriene) TMTT, 4,8,12-trimethyltrideca-l,3,7, 11-tetraene...

The male-produced volatiles eficiting responses from male and female antennae of the sap beetle, Colopterus truncatus Randall (Coleoptera Nitidulidae), were identified as (2A ,4A ,6A )-3,5-dimethyl-2,4,6-octa-triene, 2E, AE, 6T )-4,6-dimethyl-2,4,6-nonatriene and 2E, AE,6E,SE) 3,5,7-trimethyl-2,4,6,8-decatetraene. A fourth male-specific compound... 

Nine compounds from branches with leaves and green fruit from apple consistently elicited an antennal response in codling female moths (Cydia po-monella, Lepidoptera), including methyl salicylate, ( )-/3-farnesene, /3-caryo-phyllene, 4,8-dimethyl-f,3( )-7-nonatriene, (3Z)-hexenol, (Z, )-a-farnesene, ( , )-a-farnesene, linalool and germacrene D [378]. 

Potassium hydride catalyzes cyclization of cycloocta-dienes at 190° to form 84-94 of (37), while 1,4,7-cyclo-nonatriene undergoes in the presence" potassium tert-butoxide in dimethyl sulfoxide double cycloisomerization to 327"... 

Anthonomus rubi and Oxyops vitiosa) unpublished data, Gregory S. Wheeler personal communication). Primary odorants marked with bold. E-DMNT 3 -4,8-dimethyl-l,3,7-nonatriene, enantiomers not tested. 

To a distillation flask were added 107 g l,8-dibromo-3,7-dimethyl-9-(2,6,6-trimethyl-l-cyclohexen-l-yl)-2,6-nonadien-4-yne, 100 mL toluene, and 83 g triethyl phosphite. The resulting mixture was heated at 145°C for 4 h. Upon removal of the solvent, the residue was distilled through a centrifugal molecular still to give 80.9 g 3,7-dimethyl-9-(2,5,6-trimethyl-l-cyclohexen-l-yl)-2,6,8-nonatrien-4-yn-l-ylphosphonic acid diethyl ester, in a yield of 70%, m.p. 28°C. 

Sodium cyclononatetraenide was also prepared, in lower yield, by proton extraction from bicyclo[6.1.O]nonatriene with the methyl-sulphinyl carbanion in dimethyl sulphoxide [66],... 

In the case of 9,9-methylbicyclo[6.1.0]nonatriene, only the dimethyl- ran -dihydroindene is formed in a reaction that is 1/200th as fast as the isomerization of the parent. This too is consistent with slow formation of the f,c,c,c-tetraene because of attenuation of the rate of the 3,3-shift to the 5.2.0 triene (Scheme 10.16). ... 

Upon infestation of lima bean leaves (Phaseolus lunatus) with two-spotted spider mites (Tetranychus urticae), induction of ( )-P-ocimene (47) and a homomonoterpene, -4,8-dimethyl-l,3,7-nonatriene, occurs. A homosesquiterpene, (3 , 7 )-4,8,12-trimethyl-l,3,7,ll-tridecatetraene also has been observed (Dicke et al., 1990). These compounds attract another mite, Phytoseiulus persimilis, which is a predator of the two-spotted spider mite, a phenomenon known as indirect defense (Dicke et al., 1990 Takabayashi et al., 1991). When uninfested leaves are placed on moist cotton that had previously come into contact with leaves that had been infested (but had the mites removed), production of these compounds again occurred, providing evidence that induction of these kairomones occurs (Takabayashi et al., 1991). The... 

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