56889-98-6Relevant academic research and scientific papers
Pheromone specificity in Eriocrania semipurpurella (Stephens) and E. sangii (Wood) (lepidoptera: eriocraniidae) based on chirality of semiochemicals
Kozlov, Michail V.,Zhu, Junwei,Philipp, Peter,Francke, Wittko,Zvereva, Elena L.,Hansson, Bill S.,Loefstedt, Christer
, p. 431 - 454 (2007/10/03)
1966 Plenum Publishing Corporation. The fifth abdominal segment of female Eriocrania semipurpurella (Stephens) and E, sangii (Wood) contains a pair of exocrine glands. Hexane extracts of this segment were prepared from both species and analyzed by gas chromatography with simultaneous flame ionization and electroantennographic detection (EAD). For both species, the EAD active peaks were identified as nonan-2-one, (Z)-6-nonen-2-one, and (Z)-6-nonen-2-ol by means of mass spectrometry and comparison of retention indices with those of synthetic standards. Enantiomeric separation of chiral alcohols from the female extracts was achieved by gas Chromatographic analysis on a cyclodextrin column. In E. semipurpurella, a mixture of (2S,6Z)-nonen-2-ol and (2R,6Z)-nonen-2-ol (2:1) was found, whereas in E. sangii (2S,6Z)-nonen-2-ol was the predominant enantiomer and only traces of the R enantiomer were indicated by the antennal response. In field tests, a blend of the three compounds was not attractive to conspecific males. A subtractive assay showed that the alcohol in various enantiomeric mixtures was the only attractive compound, whereas addition of (Z)-6-nonen-2-one to the alcohol completely inhibited the attraction of both species. A trapping experiment including a wide range of ratios between the R and 5 enantiomers showed that baits containing 95-100% of the S enantiomer were attractive to male E. sangii, whereas males of E, semipurpurella were attracted to all tested ratios of the enantiomers. However, the response profiles of male E. semipurpurella differed between populations from southern Sweden, south Finland, and the Kola Peninsula in Russia. In south Sweden males were maximally attracted to a racemic mixture of the alcohols. At the Kola Peninsula E. semipurpurella was attracted to baits containing 95-100% of the A enantiomer. In south Finland all tested ratios between 0 and 100% R enantiomer trapped E. semipurpurella, but the trap catches appeared to be bimodally distributed with peaks around 15 and 70% R enantiomer. The trapping results suggest the existence of pheromone races or sibling species among the specimens identified as E. semipurpurella.
Synthesis of undecan-3-one; (+/-) frontalin; (+/-)-endo-, and (+/-)-exo-brevicomin under sonochemical aqueous conditions
Trehan, I. R.,Singh, Jasvinder,Arora, Ajay K.,Kaur, Jasamrit,Kad, G. L.
, p. 396 - 398 (2007/10/03)
Conjugate addition of 1-bromohexane (1) to 2-penten-3-one under sonochemical aqueous conditions, using Zn/Cu catalyst give undecan-3-one (3).Also, Zn-Cu catalysed conjugate addition of 1-bromo-2-methylpropene to 3-buten-2-one yield 6-methyl-6-hepten-2-one (6), which is tailored to furnish (+/-)-frontalin (7).Similarly, conjugate addition of 1-bromo-2-pentenes (8 and 8a) to 3-buten-2-one afford Z-6-nonen-2-one (9) and E-6-nonen-2-one (9a) respectively.An ice-cooled solution of 9/9a on tretament with m-chloroperbenzoic acid give (+/-)-exo-(10) and (+/-)-endo-brevicomin (10a) respectively.
Lewis Acid-Induced Reactions of γ-Trialkylstannyl Ketones. Cyclization, Carbon-Carbon Bond Cleavage, and 1,5-Hydride Shift
Sato, Tadashi,Tachibana, Kazutaka,Kawase, Akira,Hirose, Tomokazu
, p. 937 - 940 (2007/10/02)
γ-Trialkylstannyl ketones underwent cyclobutanation, C-C bond cleavage, or 1,5-hydride shift, depending upon the substitution pattern of the substrates.
Two convenient syntheses of brevicomin
Dandge, Chitra N,Naik, D G,Kapadi, A H
, p. 617 - 619 (2007/10/02)
Synthesis of brevicomin, 7-ethyl-7-methyl-6,8-dioxabicyclooctane (1), the aggregation pheromone of Western pine beetle, Dendroctonus brevicomis, by simple routes is described.
Oxidative Grob Fragmentation of γ-Tributylstannyl Alcohols with a Combination of Iodosylbenzene, Dicyclohexylcarbodiimide, and Boron Trifluoride
Ochiai, Masahito,Ukita, Tatsuzo,Iwaki, Shigeru,Nagao, Yoshimitsu,Fujita, Eiichi
, p. 4832 - 4840 (2007/10/02)
Exposure of cyclic γ-stannyl alcohols, prepared from cyclic vinyl ketones, to a combination of iodosylbenzene, dicyclohexylcarbodiimide, and boron trifluoride-diethyl ether in dichlorometane undergoes an oxidative Grob fragmentation to give unsaturated carbonyl compounds.The dicyclohexylcarbodiimide in this reaction apparently activates iodosylbenzene and decreases Lewis acidity of boron trifluoride.The fact that the iodine(III)-mediated Grob fragmentation proceeds stereospecifically suggests the fragmentation is concerted.The fragmentation, combined with conjugate addition of (tributylstannyl)lithium and reduction or alkylation, offers an efficient procedure for the reductive and alkylative ring opening of cyclic vinyl ketones.Since cis-benzyl ether 36, after quenching of the reaction mixture with aqueous NH4Cl, afforded the chlorostannane 37, the reaction mechanism involving the formation of iodine(III) species 32 with two oxygen ligands at iodine proposed.
SYNTHESIS OF β-SILYL KETONES VIA REACTION OF TRIMETHYLSILYLLITHIUM WITH UNSATURATED HYDRAZONES. APPLICATION TO THE SYNTHESIS OF BREVICOMIN
Hudrlik, Paul F.,Hudrlik, Anne M.,Yimenu, Tilahun,Waugh, Morris A.,Nagendrappa, G.
, p. 3791 - 3804 (2007/10/02)
Trimethylsilyllithium undergoes conjugate addition to dimethylhydrazones of α,β-unsaturated ketones.The resulting metalloenamine intermediates can be alkylated, and the resulting hydrazone products cleaved to give α-substitued-β-silyl ketones.These reacti
β-Halogeno Ether Synthesis of Olefinic Alcohols: Stereochemistry of the Ring-scission of 2-Substituted 3-Halogenotetrahydro-pyrans and -furans
Crombie, Leslie,Wyvill, Robert D.
, p. 1983 - 1996 (2007/10/02)
The stereochemical outcome of the sodium ring-scission of 2-substituted 3-halogenotetrahydro-pyrans and -furans, with 2-substitution represented by alkyl, alkenyl or aryl, is presented.Although the cis- and the trans-tetrahydropyran scissions are hyghly stereoselective for (E)-5-substituted pent-4-enol, this stereoselectivity breaks down when the 2-substituent is conformationally undiscriminating (deuterium) or has substantial anomeric effects (methoxy).Consideration of this, along with conformational data from the preceding paper, provides an explanation of the stereoselectivity of the tetrahydropyran scission.Evidence against a radical, and for a carbanion intermediate is presented and a common, very rapidly inverting, 3-carbanion is considered to be formed from either cis- or trans-stereoisomers.Ring scission is also rapid (the carbanion cannot be trapped), but less rapid than carbanion inversion, and takes place before the slower conformational inversion can occur so that the (E)/(Z)-nature of the unsaturated alcohol produced is controlled by the initial tetrahydropyran conformation.The unstereospecific nature of the ring scission of both cis- and trans-2-alkyl-3-chlorotetrahydrofurans is explained as a consequence of their existence in conformational equilibria. The high stereoselectivity of the ring scission of cis- and trans-3-chloro-2,3-dimethyltetrahydropyrans, and the poor stereoselectivity of the scission of 2-alkyl-3-chloro-2-methyltetrahydrpyrans, is explained; the reaction of sodium with 2-butyl-3,3-dichlorotetrahydropyran is considered.Using the ring-scission of 3-chlor-2-ethyltetrahydropyran, short syntheses of (+/-)-endo-brevicomin are described to illustrate the utility of β-halogen ether synthesis.
Stereochemistry of an Oxidative 1,4-Fragmentation of γ-Stannyl Alcohols with a Hypervalent Organoiodine Compound and the Synthesis of erythro-6-Acetoxyhexadecan-5-olide
Ochiai, Masahito,Ukita, Tatsuzo,Nagao, Yoshimitsu,Fujita, Eiichi
, p. 637 - 638 (2007/10/02)
Iodine(III)-mediated oxidative 1,4-fragmentation of the 2,3-trans- and 2,3-cis-3-stannyl alcohols, (6a,b) and (6c), proceeds stereospecifically to give the E- and Z-enals, (7) and (8), respectively, and stereoselective synthesis of the mosquito pheromone,
Convenient Synthetic Route tp 6,8-Dioxabicyclooctanes, the Aggregation Pheromone Components of Bark Beetles
Joshi, Navalkishore N.,Mamdapur, Vasant R.,Chadha, Mohindra S.
, p. 2963 - 2966 (2007/10/02)
Convenient syntheses of (+/-)-frontalin (I) and (+/-)-brevicomins (IIa) and (IIb) were achieved from pent-4-en-1-ol (2) and pent-4-yn-1-ol (3).In a few simple and unambiguous steps, the alkenol (2) and the alkynol (3) were transformed into the acetal bromide (7) and the alkenyl bromides (14) and (17), respectively.Acylation of Grignard reagents of these bromides provided the corresponding methyl ketones (8), (15), and (18), the key intermediates for the synthesis of the title bicyclic acetals.The ketone (8) was converted into the olefin (9) which, on epoxidation followed by acid hydrolysis, yielded (+/-)-frontalin, whereas epoxidation of the alkenones (15) and (18) and subsequent cyclization afforded exo- and endo-brevicomin, stereoselectively.
