The synthesis of the drugstore beetle pheromone (Stegobinone)

2,3-Dihydro-2,3,5-trimethyl-6-(1-methyl-2-oxobutyl)-4H-pyran-4-one ($\text{1}$ (Stegobinone), the sex pheromone of the drugstore beetle, was successfully prepared from 4,6-dimethyl-3,5,7-nonatrione ($\text{2}$) by a biogenetically plausible scheme.     

4.6-dimethyl-7-hydroxy-nonan-3-one,a sex pheromone of the cigarette beetle (Lasioderma serricorne F.)

A structure of the sex pheromone produced by the female cigarette beetle (Lasioderma serricorne F.) is established as 4,6-dimethyl-7-hydroxy-nonan-3-one (Ia) by chemical and spectroscopic evidences.     

Identification of the sex pheromone of Phyllophaga cuyabana (Coleoptera: Melolonthidae)

Phenol 1 and p-cresol 2 were identified as sex pheromone components released by females Phyllophaga cuyabana. The compounds are produced in a ratio of 1:1, as detected by the analysis of pheromone gland extract. In field experiments, the capture of males in traps baited with the synthetic blend were significantly higher than in control traps.     

Determination of the absolute configuration of the sex pheromone of the obscure mealybug by vibrational circular dichroism analysis

Comparison of theoretical and experimental vibrational circular dichroism (VCD) spectra of an enantiopure synthetic sample of the obscure mealybug sex pheromone allowed the determination of the absolute configuration of the insect's pheromone.     

Concise asymmetric synthesis of the sex pheromone of the tea tussock moth

A concise asymmetric total synthesis of the sex pheromone of the tea tussock moth has been achieved from commercially available starting materials. The chiral moiety was introduced by Evans’ template and the key CC bond construction was accomplished through Julia-Kocienski coupling and Wittig olefination. The salient characteristic of our synthetic route is that it is protecting a group free.     

Elephant albumin: a multipurpose pheromone shuttle

(Z)-7-dodecenyl acetate (Z7-12:Ac) is present in the urine of female Asian elephants (Elephas maximus) approaching ovulation and functions as a female-to-male sex pheromone. Here we show that a significant fraction of the pheromone in the urine is bound to a protein, elephant serum albumin (ESA), and provide evidence for key physiological functions of urinary ESA. Our biochemical and behavioral experiments suggest a three-fold role of ESA in pheromone signaling: (1) transporting Z7-12:Ac from serum into urine; (2) extending the presence of the pheromone in the environment without hampering detection; and (3) targeting pheromone delivery to chemosensory organs through localized release of the ligand induced by a pH change. The exploitation of albumin in pheromone transport clearly distinguishes the elephant from other mammals studied, and complements the uniqueness of elephant anatomy, physiology, and behavior.     

Synthesis of a stereoisomeric mixture of 2,3-dihydro-2,3,5-trimethyl-6-(1-methyl-1-oxobutyl)-4H-pyran-4-one,the pheromone of the drugstore beetle

Reaction of acetaldehyde with the trianion of 4,6-dimethylnonane-3,5, 7-trione followed by acidification yielded a stereoisomeric mixture of the pheromone of $\text{Stegobium}$$\text{paniceum}$ L.     

(R)-4-Menthenone in the synthesis of optically pure sex pheromone of the peach leafminer moth (Lyonetia clerkella)

The synthesis of (14S)-methyloctadec-1-ene, sex pheromone of the peach leafminer moth (Lyonetia clerkella), is described to demonstrate a new potential of the synthetic use of (R)-4-menthenone.     

Facile Synthesis of (Z,E)-9,11-Hexadecadienal,the Major Sex Pheromone Component of the Sugarcane Borer Diatraea saccharalis: An Efficient Strategy for Synthesis of (Z,E)-Dienic Pheromones

Practical and improved procedures for the synthesis of 7-bromo-(Z,E)-4,6-heptadienal by Pd(II)-catalyzed coupling reaction were developed. Based on the improved method, an efficient and stereoselective synthesis of (Z,E)-9,11-hexadecadienal, the main pheromone component of the sugarcane borer, Diatraea saccharalis, was achieved in 38% overall yield, which more desirable then previously reported methods. The stereochemistry relied on cross-coupling between Grignard reagent and protected 7-bromo-(Z,E)-4,6-heptadienal. The concise and facile synthetic strategy described herein provided a generally synthetic approach to other (Z,E)-dienic compounds.     

Insect pheromone components: Use of 13C NMR spectroscopy for assigning the configuration of CC double bonds of monoenic or dienic pheromone components and for quantitative determination of Z/E mixtures

Several insect sex pheromone components and structural analogues have been characterized by ¹³C NMR spectroscopy. The evaluation of the difference between the chemical shift values of the allytic carbons present in the diunsaturated pheromone components and those of the carbons having the same position on the n-alkane chain of the corresponding saturaated compounds was used to assign the configuration of the CC double bonds present into such dienic compounds. The technique avoids the need to use the nuclear Overhausser effect; it allows quantitative evaluation, with good accuracy, of the stereoisomeric composition of mixtures of synthetic monoenic or dienic pheromone components such as (Z)- and (E)-9-tetraceden-1-yl acetate and (Z)- and (E)-9,11-dodecadien-1-yl acetate.     

Detection and synthesis of a synergist of the sex pheromone of the cotton bollworm

The synergisic properties of docosa-5Z, 17Z-diene — one of the by-products of the synthesis of the synthetic cotton bollworm pheromone — have been revealed.A. S. Sadykov Institute of Bioorganic Chemistry, Academy of Sciences of the Republic of Uzbekistan, Tashkent, fax 627071. Translated from Khimiya Prirodnykh Soedinenii, No. 1, pp. 130–132, January–February, 1994.     

Facile routes to natural acyclic polyenes syntheses of spilanthol and trail pheromone for termite

The synthetic procedures for spilanthol and trail-following pheromone for a southern subterranean termite were described. The syntheses heavily depend on the new diene synthesis using titanium reagent.     

Synthesis of a biologically active analog of the sex pheromone of cigarette beetle (<Emphasis Type="Italic">Lasioderma serricorne</Emphasis>)

A simple synthesis of a diastereomeric mixture of 7-hydroxy-4,6-dimethylnonan-3-ones was carried out. In the biological action, it is an analog of serricornin, the sex pheromone of the cigarette beetle (Lasioderma serricorne). Dedicated to Academician N. K. Kochetkov on the occasion of his 90th birthday. __________ Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 5, pp. 1218–1221, May, 2005.     

Chemical synthesis of ComX pheromone and related peptides containing isoprenoidal tryptophan residues

The ComX pheromone is a post-translationally modified oligopeptide that stimulates natural genetic competence controlled by quorum sensing in Bacillus subtilis. Recently, the structure of the ComX_RO-E-2 pheromone produced by strain RO-E-2 was determined. Based on the NMR analysis, a geranyl group is bound to the tryptophan residue, which results in the formation of a tricyclic ring structure. It was proposed that one of the four possible stereochemical isomers was based on a conformational search for model compounds and the assumption that amino acid residues in the natural pheromone have the l-configuration. All possible modified tryptophan residues and the corresponding ComX_RO-E-2 peptides were synthesized to confirm the precise stereochemistry. Here, the synthesis of the modified tryptophan derivatives was reported in detail. It was succeeded in synthesizing four optically active modified tryptophan methyl esters from which the four diastereomeric ComX_RO-E-2 peptides were prepared. Since only one of the four diastereomers was spectroscopically identical to the natural pheromone and exhibited biological activity, the absolute structure of the ComX_RO-E-2 pheromone was able to be established unambiguously. Furthermore, it was noticed that two other bioactive pheromones were present in the culture broth that were co-purified with ComX_RO-E-2 pheromone. These pheromones were presumed to be the N-terminal truncated peptides of ComX_RO-E-2 pheromone, i.e., [2-6]ComX_RO-E-2 and [3-6]ComX_RO-E-2, by LC-MS and NMR analyses. Using Fmoc solid-phase peptide synthesis, ComX_RO-E-2 pheromone and the [2-6]ComX_RO-E-2 and [3-6]ComX_RO-E-2 peptides were prepared. The synthetic peptides were identical to the natural pheromones and also showed significant biological activity.     

Analytical studies of Spodopteralittoralis sex pheromone components by electroantennography and coupled gas chromatography-electroantennographic detection

In this paper we present analytical studies of the sex pheromone components of the Egyptian armyworm Spodoptera littoralis (Lepidoptera, Noctuidae) by electroantennography (EAG) and coupled gas chromatography-electroantennographic detection (GC-EAD). EAG responses in three different preparations, using an insect's head, an excised antenna and a live insect, have been recorded. EAG depolarizations of live insects were significantly higher than those elicited by the insect's head or the excised antenna. The responses were dose-dependent. Live insects also allowed regular pheromone stimulations for 40 min with only 38% decrease of the EAG initial depolarization. The synthetic pheromone blend elicited the highest EAG activity (2.0+/-0.3 mV), followed by the major compound (Z,E)-9,11-tetradecadienyl acetate (I) (1.54+/-0.1mV), and the minor components (Z)-9-tetradecenyl acetate (II), (E)-11-tetradecenyl acetate (III), tetradecyl acetate (IV) and (Z)-11-tetradecenyl acetate (V) (1.21-1.32 mV range). (Z,E)-9,12-tetradecadienyl acetate (VI), although not present in the pheromone blend of our strain, also showed an EAG activity (1.32+/-0.09 mV) similar to that of the monoenic components. GC-EAD responses confirmed the composition of the sex pheromone blend, the major response being elicited by the main component I followed by the other minor compounds II-V. The new dienic compound found in the female pheromone gland, (E,E)-10,12-tetradecadienyl acetate (VII), was not electrophysiologically active. Regarding sensitivity, the minimum amount detectable to elicit an antennal response in our GC-EAD system was 15 pg of the major component. In our system, which was built with cheap and easily available materials, no cooling of the effluent at the outlet of the chromatographic column is required.     

Synthesis of (2s, 3r, 7rs)-stegobinone [2,3-dihydro-2,3,5-trimethyl-6-(1-methyl-2- oxobutyl)-4h-pyran-4-one] and its (2r, 3s, 7rs)-isomer : The pheromone of the drugstore beetle

Reaction of acetaldehyde with the trianion of 4,6-dimethylnonane-3,5,7-trione followed by acidification yielded a stereoisomeric mixture of stegobinone, the pheromone of Stegobium paniceum L. Acylation of the dianion derived from 4-methylheptane-3,5-dione with a mixed anhydride prepared from (2R, 3S)-3-hydroxy-2-methylbutanoic acid or its enantiomer led to (2S,3R,7RS)- or (2R, 3S, 7RS)-stegobinone. The natural pheromone possesses (2S,3R)-stereochemistry.     

A concise and stereoselective chemoenzymatic synthesis of Sitophilate,the male-produced aggregation pheromone of Sitophilus granarius (L.)

(2S,3R)-Sitophilate, the male-produced aggregation pheromone of the granary weevil Sitophilus granarius (L.) was prepared stereoselectively using a novel chemoenzymatic approach in 50% overall yield. The synthetic design was based on an enantioselective fungal reduction of ethyl 2-methyl-3-oxopentanoate with a strain of Aureobasidium pullulans (CCM H1), followed by a Mitsunobu inversion at C3. The last step in the synthetic sequence was a lipase-mediated transesterification using the commercially available Candida antarctica B lipase (CaL B, Novozym 435) using microwave irradiation under solvent-free conditions.     

A concise synthesis of sex pheromone of mediterranean fruit fly,Ceratitis capitata via lithiated carbanion derived from enephosphoramide

A novel and versatile synthetic approach to the preparation of (E)‐non‐6‐en‐1‐ol, a sex pheromone of the Mediterranean fruit fly, Ceratitis capitata, is presented. This pheromone can be viewed as potential active component for lures designed to control and eradication of Mediterranean fruit fly. The described protocol is a six‐step reaction sequence producing the desired compound with 28% overall yield from commercially available and inexpensive starting material and total E stereoselectivity of the double bond present in final structure. The key to the success of the presented strategy is application of lithiated α‐allylphosphoramido carbanions and their reaction with halogenated acetals. © 2010 Wiley Periodicals, Inc. 21:139–147, 2010; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/hc.20588     

Enantioselective synthesis of (S)-3,7-dimethyl-2-oxo-6-octene-1,3-diol: a Colorado potato beetle pheromone

The recent identification of a male-produced aggregation pheromone [(S)-3,7-dimethyl-2-oxo-6-octene-1,3-diol, (S)-CPB] offers a new tool for Colorado potato beetle (CPB) management. We developed a novel synthetic approach to produce CPB pheromone in seven steps and 46.54% overall yield. Grignard reaction, oxidation, and stereoselective methylation using organometallic reagent are the key steps in the commercially viable total synthesis, generating CPB pheromone in 98.6% enantiomeric purity and gram quantity.     

Trail pheromone of Kalotermes flavicollis

The trail pheromone of the termiteKalotermes flavicollis Fabr. has been isolated with the aid of column, liquid, and gas chromatography. Four of its components have been identified by PMR and chromato-mass spectrometry: nonan-l-ol, decan-l-ol, undecan-l-ol, and dodecan-l-ol, which are present in the natural trail pheromone in a ratio of 1:2:4:4. This has been confirmed by comparison with standard substances by means of gas chromatography and biotesting.Institute of the Physiology of Active Substances, Academy of Sciences of the USSR, Chernogolovka. Translated from Khimiya Prirodnykh Soedinenii, No. 1, pp. 129–132, January–February, 1989.