10-methyl-2-tridecanone

Southern corn rootworm. The structure of the southern corn rootworm has been defined as 10-methyl 2-tridecanone, XI (Figure 16) (5J3). Alkylation of undecanoic acid with n-propyl bromide was followed by conversion to the diastereomeric amides with either (S)- or (R)-a-methylbenzylamine that had been purified previously by recrystallization of D and L tartaric acid salts, respectively. Recrystallizations of these amides from ethanol (4 was sufficient) gave 32% yields of pure (>99.5%) diastereo-mers (Figure 16). Hydroxyethylation labilized the amides toward hydrolysis. It was convenient to intercept the aminoesters and reduce them with LAH. The resulting carbinols were than carried forward in standard manner to provide the ketones. 

The pheromone of the southern corn rootworm (SCR), D. undedmpunctata howardii Barber, was identified as (R)-10-methyl-2-tridecanone (40). Since it has only one asymmetric carbon, it can exist in only two enantiomeric forms. Synthesis of both the (R)- and (S)-enantiomers by Sonnet (41) in high enantiomeric purity again provided material for field tests. SCR males respond only to the (R)-enantiomer in the field. 

The sex pheromone structure, 10-methyl-2-tridecanone, was synthesized using the carboxyl group as the source of the methyl branch (lA) (Figure 6). Undecylenic acid was a-propylated and resolved via amides. The procedure followed allowed us to obtain the alcohols,(R)- and (S)-2-propyl-10-undecenol (>99.6% ee). The corresponding bromide was reduced with lithium triethylborohydride (15) then the double bond was converted to a methyl ketone by a) oxymercuration, b) reduction of the C-Hg bond with sodium borohy-dride, and c) oxidation with dichromate. The male southern corn rootworm responds only to the (R)-configuration no biological activity was noted for the (S)-enantiomer. Therefore, in this instance the racemic compound would be predicted to monitor this species adequately. 

Like secondary alcohols, ketones are not common constituents of the cuticular lipids of insects (Lockey, 1988). The cuticular lipid of the female housefly, M. domestica, contains 6% of an unsaturated ketone, (Z)-14-tricosen-10-one (Uebel et al., 1978) and lesser amounts of tricosan-10-one and heptacosen-12-one (Mpuru et al 2001). The cuticular lipids of several species of Drosophila contain C13-C17 saturated and unsaturated ketones, including 2-tridecanone and 2-pentadecanone in Drosophila hydei (Moats et al., 1987), 10-heptadecen-2-one in D. mulleri (Bartelt et al., 1989), and 2-pentadecanone in D. busckii (Schaner et al., 1989). Odd-chain ketones (2-nonadecanone, 2-heneicosanone and 2-tricosanone) comprise 1% and 3% of adult male and female cuticular lipids, respectively, of the pecan weevil, Curculio caryae (Espelie and Payne, 1991). The cuticular lipids of mature screwworm females, C. hominivorax, contained small quantities of two C31 ketones the symmetrical ketone, 16-hentriacontanone and the methyl-branched ketone, 21-methyl-7-hentriacontanone (Pomonis etal., 1993). 

Maltol Isobutyrate 2-Methoxy 3-(or 5- or 6-) Isopropyl Pyrazine 5H-5-Methyl-6,7 -dihydrocyclopenta[b]pyrazine 5-Methyl Furfural Methyl Furoate Methyl Hexanoate Methyl Isovalerate 5-Methyl 2-Phenyl 2-Hexenal Methyl Thiobutyrate Methyl Valerate P-Naphthyl Ethyl Ether Phenyl Ethyl Cinnamate Phenyl Ethyl Propionate Propyl Formate Propyl Mercaptan Salicylaldehyde 8-T etradecalactone 2-Tridecanone... 

A further example of enzymatic Baeyer Villiger monooxygenation is the insertion of oxygen by 2-tridecanone oxygenase from Pseudomonas cepacia into aliphatic methyl ketones, yielding the corresponding alkyl acetates 395. 

D.10) (D.10) 2-Tridecanone, tridecan-2-one, methyl undecyl ketone 1593-08-8] FEMA 3388... 

A novel two carbon analog of 8, namely the 7-methyl-6(Z)-octadecenoic acid was recently identified in the holothurian Holothuria mexicana [27]. However, both Z and E stereoisomers were later shown to originate from the bacterium Vibrio alginolyticus [27]. Therefore, the real source of 7-methyl-6-octadecenoic acid is also bacterial. Both Z and E isomers of 7-methyl-6-octadecenoic acid were synthesized as shown in Fig. (9). In this short synthesis (little more than one step) a Wittig coupling of (6-carboxyhexyl)triphenylphosphonium bromide with 2-tridecanone readily afforded a 1 1 mixture of 7-methyl-6(Z)-octadecenoic... 

Methylthio-l,2,3-trithiane see charamin. 12-Methyltridecanal see meat flavor. (IB-lO-Methyl-2-tridecanone see leaf beetles. Methyl 2,6,10-triinethyltridecanoate see bugs. M-Methyltyramine see j3-phenylethylamine alkaloids. 

Accession PI 134417 is highly resistant to sexta due to the acute toxicity of its foliage to young larvae (40-41), This resistance is conditioned by the presence of the 13-carbon methyl ketone, 2-tridecanone, in the tips of type VI (42) glandular tricho-mes (43-46),... 

Undecanone, the 11-carbon methyl ketone, also occurs in the type VI trichomes of PI 134417 and is active against zea and several other pest species (59-60), It is less acutely toxic than 2-tridecanone against neonate zea (59) and is less abundant (x = 1.1 ug vs. 6.2 ug/trichome tip for 2-tridecanone in PI 134417), However, in combination, 2-tridecanone and 2-undecanone are... 

In field cage studies in which zea larvae on several plant lines were exposed to adult parasitoids (one plant line per cage), percent paras itization by both species was significantly lower on BC2, (a backcross ((L, esculentum x PI 134417) x PI 134417) line with intermediate levels of 2-tridecanone and glandular trichome density), and PI 134417 than on L. esculentum and the Fi hybrid (L. esculentum X PI 134417) (Table ViTT. This pattern reflects levels of 2-tridecanone-mediated resistance to sexta. These data indicate that fewer zea larvae are parasitized on the more resistant plant lines but do not indicate whether this is due to elevated densities of glandular trichomes or methyl ketones, or both. 

Methyl undecylenate. See Methyl 9-undecenoate Methyl undecanoate Methyl undecyf ketone. See 2-Tridecanone Methyl 2-undecynoate CAS 10522-18-6 FEMA 2751... 

The secretion of the East African species A. messinae contains the eudesmane but the minor component is limonene (Meinwald etal., 1978). Of two sympatric species, A. unidentatus produces mainly methyl ketones, principally 2-tridecanone, and A. lonnbergianus has no hexane-extractable material. The North American species, A. wheeleriproduces a sesquiterpene hydrocarbon only (Prestwich, 1979b), while the Australian species, A. herbertensis and A. laur-contain monoterpene hydrocarbons, the former terpinolene (>98%) and a-phellendrene and the latter limonene and -pinene (Moore, 1968). 

This cuprate also underwent the conjugate addition with acyclic enones, for example, 2-hexene-4-one, to give 5-methyl-3-tridecanone in 47% yield. We have not attempted further optimization. Reaction of this calcium cuprate with a sterically hindered enone, for example, isophorone, produced <3% of the desired compound in 24h. The isolated yield, however, increased to 84% when the additives BF3 etherate and chlorotrimethylsilane [12] were used. In the aryl case, / -tolylcalcium cuprate also underwent this transformation with 2-cyclohexenone to give 3-(p-methylphenyl)cyclohexanone in reasonable yield (Table 9.3). 

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