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Covering: 1979 to 2014 This article comprehensively reviews the syntheses of all known sex pheromones of scales and mealybugs, describes how they were identified, and how the synthetic pheromones are used in insect management.

Wheat is the most widely cultivated plant in the world, providing more than 20 % of the food calories consumed [1]. The Hessian fly, Mayetiola destructor (Say), (Diptera: Cecidomyiidae), is one of the most destructive pests of wheat and is found in most of the major wheat-growing areas of the world [2]. Due to the feeding habit of the larva and the type of damage it produces, early infestations by Hessian fly are extremely difficult to detect or predict. Female Hessian flies are known to produce a sex pheromone that elicits upwind flight by males [3] and, given the widespread use of synthetic sex pheromones in pest management programs [4], it is very likely that this sex pheromone could find great utility in controlling this pest. As well as containing a large number of pest species, the family Cecidomyiidae is of evolutionary interest because of its rapid rate of species formation relative to a lesser rate of speciation in related families of Diptera [5]. We report here the first identification of a cecidomyiid sex pheromone, that of the Hessian fly, as (2S)(E)-10-tridecen-2-yl acetate (Fig. 1). The crude sex pheromone was obtained by dissecting the terminal segments of the ovipositors of female Hessian flies, and extracting them in pentane. The activity of extracts, fractions of extracts, and synthetic chemicals was determined

(1991). AN EFFICIENT LARGE SCALE PREPARATION OF (S)-1,1,2-TRIPHENYLETHANEDIOL 2-ACETATE. Organic Preparations and Procedures International: Vol. 23, No. 2, pp. 173-180.

We describe the synthesis of the novel bifunctional linker molecule 2-methyl, 2-(3-carboxypropyl)-cyclopent-4-en-1,3-dione and various related compounds. These compounds are highly thiol-specific.

Seven aziridines and azetidines, either unsubstituted on ring nitrogen or bearing N-acyl (N,N-dimethylcarbamyl or propionyl) groups, were reacted with N2O5 in halogenated solvents with the following results:- the behaviour of the aziridines was highly dependent on the N-substituent, giving respectively dinitrate esters, nitramine-nitrate or predominantly uncharacterisable products, whereas the azetidines gave in all cases N-nitroazetidine. The different behaviour is believed to result from ring strain effects.

The effect of oxidation and reduction conditions upon the morphology of polycrystalline silver catalysts has been investigated by means of in situ Fourier-transform infrared (FTIR) spectroscopy. Characterization of the sample was achieved by inspection of the νas(COO) band profile of adsorbed formate, recorded after dosing with formic acid at ambient temperature. Evidence was obtained for the existence of a silver surface reconstructed by the presence of subsurface oxygen in addition to the conventional family of Ag(111) and Ag(110) crystal faces.Oxidation at 773 K facilitated the reconstruction of silver planes due to the formation of subsurface oxygen species. Prolonged oxygen treatment at 773 K also caused particle fragmentation as a consequence of excessive oxygen penetration of the silver catalyst at defect sites. It was also deduced that the presence of oxygen in the gas phase stabilized the growth of silver planes which could form stronger bonds with oxygen. In contrast, high-temperature thermal treatment in vacuum induced significant sintering of the silver catalyst.Reduction at 773 K resulted in substantial quantities of dissolved hydrogen (and probably hydroxy species) in the bulk silver structure. Furthermore, enhanced defect formation in the catalyst was also noted, as evidenced by the increased concentration of formate species associated with oxygen-reconstructed silver faces.

The photochemical reaction between [60]fullerene and N-ethoxycarbonylazepine, formed in situ by light-induced decomposition of ethyl azidoformate in benzene, produces two photoadducts in the ratio of 4:1 by formal [2 + 4] and[2 + 6] cycloaddition reactions as established by a series of high-field (600 MHz) NMR experiments.

Upon treatment with zinc in glacial acetic acid, N-oxycarbonylaziridino[2′,3′: 1,2][60]fullerenes 3 undergo a reversible reductive cleavage of the bridgehead C–C bond to provide the first examples of birdged fulleroids 4 having an open 6,6-ring juncture; deprotection of the N-tert-butoxycarbonyl derivative 4a allows the convenient synthesis of C60H2NH 5, the parent member of this new class of bridged fulleroids.

An overview of the utility of dinitrogen pentoxide in the synthesis of energetic materials is described. New nitration methodologies have been developed which overcome many of the drawbacks of conventional mixed acid media, especially when dealing with sensitive substrates. Two nitration systems systems are discussed: Dinitrogen pentoxide in pure nitric acid and dinitrogen pentoxide in organic solvents. Advantages are described.

In a search for a generic synthesis methodology to produce microporous, nonoxide ceramics, pyrolysis of silicon-based preceramic polymers has been studied in inert (He or Ar) and reactive (NH3) atmospheres over the temperature range 25−1300 °C. Pyrolysis of polysilazanes in an inert atmosphere in the absence of additives produced only low-density, nonmicroporous solids. However, four successful approaches to induce microporosity were developed, involving controlled reaction of selected low molecular weight polysilazane preceramic polymers. The first method employs the formation of colloidal polysilazane mixtures with micron-size particles of ceramics such as Si3N4, SiC, and AlN, followed by their pyrolysis in He or NH3 to form a ceramic−ceramic composite. The second method involves the synthesis of a nanoscale, polysilazane-stabilized metal colloid of a noble or transition metal and its conversion to a metal− or cermet−ceramic composite by pyrolysis in He or NH3. In the third method, a polysilazane is pyr...

Sexually mature male stink bugs, Thyanta pallidovirens , release a male-specific blend of volatiles, including several sesquiterpene hydrocarbons, and the highly conjugated ester methyl (2 E ,4 Z ,6 Z )-deca-2,4,6-trienoate 1 . The latter compound was synthesized, and found to rearrange under GC conditions via a 1,7 sigmatropic rearrangement. © 1997 Elsevier Science Ltd.

A new nitration of naphthalene affords as major products 1,4-disubstituted naphthalenes and as minor products 1,2-disubstituted naphthalenes. By use of ceric ammonium nitrate suspended on silica gel, or in homogeneous solution, nitration of naphthalene in the presence of alcohols, sodium- or tetrabutyl ammonium- nitrite and acid gives alkoxynitronaphthalenes. A preparation of 1-nitronaphthalene i is described under heterogeneous conditions.

N-Aryl-S,S-diphenylsulfilimines with unusual substitution patterns have been prepared by reacting the novel nitrogen nucleophile N-lithio-S,S-diphenylsulfilimine with a range of activated aromatic substrates. N-Lithio-S,S-diphenylsulfilimine is not only able to displace chloro groups in conventional aromatic nucleophilic substitution reactions, but also, unlike S,S-diphenylsulfilimine itself, can attack at hydrogen-bearing positions in ‘vicarious’ aromatic nucleophilic substitutions of hydrogen.

Short, efficient syntheses yielding products of very high isomeric purity have been developed for (10E,12E,14E)-hexadeca-10,12,14-trienal 1 and the (10E,12E,14Z)-isomer 2, the key pheromone components of the tobacco hornworm moth Manduca sexta. The penultimate (EEZ)-trienol, and aldehyde 1, were freed from isomeric impurities by selective reaction of the impurities with tetracyanoethylene. (EEE)-Aldehyde 2 was prepared by Wittig reaction of (2E,4E)-hexa-2,4-dienyltriphenylphosphonium bromide with 10-acetoxydecanal, deprotection, selective crystallization of the (EEE)-trienol from the resulting mix of isomers, and oxidation. The yield of the (EEE)-trienol was increased further by iodine-catalyzed isomerization of the mix of isomers in the liquor, and further recrystallization.

A facile asymmetric synthesis of N -alkyl-3,4-dihydroxy-5-alkylpiperidines has been developed, which is based on an asymmetric alkylation reaction of the SAMP hydrazone of N -BOC piperidinone.

Sexually mature females of an important agricultural pest, the vine mealybug Planococcus ficus, produce the monoterpene (S)-lavandulol and the corresponding ester, (S)-(+)-lavandulyl senecioate. The racemic ester was highly attractive to mature male mealybugs, whereas lavandulol was not. The naturally produced 2:5 blend of lavandulol and the ester also was no more attractive than the ester alone.

Procedures for efficient mono- and di-nitration of aromatic substrates have been developed using ceric ammonium nitrate suspended in dichloromethane in the presence of 2 equiv. of sulfuric acid. By suspending the sulfuric acid on silica gel following nitration, products are easily isolated by filtration and evaporation of solvent. In these nitrations ceric ammonium nitrate can be replaced by other metal nitrates, for example potassium- or tetrabutylammonium-nitrate. In contrast the nitration of naphthalene by ceric ammonium nitrate in the presence of methanol and sulfuric acid affords a mixture of 1,4- and 1,2-methoxynitronaphthalenes, but these nitrations cannot be achieved using potassium or tetrabutylammonium nitrate. The mechanism of this nitration/oxidation is discussed.

Novel nitration systems comprising nitric acid, trifluoroacetic anhydride and zeolite Hβ, with or without acetic anhydride, are described. The system having no acetic anhydride is more active and readily nitrates deactivated substrates such as nitrobenzene, benzonitrile, benzoic acid or 4-nitrotoluene to give predominantly the product substituted meta to the deactivating group.The system incorporating acetic anhydride is more moderate in activity, and nitrates moderately deactivated systems such as halogenobenzenes quantitatively within two hours at ice–salt bath temperature, and provides very high selectivity for the para-nitrated product. This system also nitrates 2-nitrotoluene to give high selectivity for 2,4-dinitrotoluene production. Furthermore, the system can be used for direct double nitration of toluene and gives a 92% yield of 2,4-dinitrotoluene with a 2,4-∶2,6-dinitrotoluene ratio of 25∶1. Even greater selectivity (96% yield and 70∶1 selectivity) can be achieved in the latter reaction by conducting the reaction in one flask but in two stages, with trifluoroacetic anhydride added only in the second stage. p

This paper describes progress in the development of clean nitration and azidation methods, based upon the use of solid supports such as clays and zeolites.