IL37921A - Terpene aryl ethers,their manufacture and their use for pest control - Google Patents

Description

©ιη'σηι D-nx" ,o's n ο'τηκ 'IK 79-10 New terpene aryl ethers, their manufacture and their use for pest control CIBA-GKIGY AG. -7200/l+2/A-I/= The present invention relates to novel terpene aryl ethers having valuable pesticidal properties, to their production and to their use.

More particularly the present invention relates to terpene aryl ethers of the formula I wherein Z, and Z, together represent an additional bond or an oxygen bridge between the carbo atoms to which they are attached.

R, and R, independently of each other, represent a methyl or ethyl group, and either (i) R, represents an alkenyloxy or halo-alkenyloxy group each containing from 2 to 4 carbon atoms; an (alkyl- thio)carbonyl or alkanoylamino group each containing from 2 to 5 carbon atoms; a phenoxy, benzyloxy or benzoyl group; or a phenyl-alkyl group having from 1 to 3 carbon atoms in the alkyl moiety, while R, represents a hydrogen atom, or (ii) R-j represents a hydrogen atom, while R^ represents a propargyloxy" group, which compounds have been found to posess valuable pest -cidal, in particular insecticidal activity.

Of the compounds of the formula I those wherein R^ represents an allyloxy, 3-chloro-allyloxy, 7-chloro-allyloxyj methallyloxy, ,acetylamino, benzoyl, benzyl, phenoxy or (methylthio)carbonyl group and R^ represents a hydrogen atom, and those wherein R-^ represents a hydrogen atom and R^ represents a propargyloxy group are preferred on account of their particularly marked insecticidal properties.

In the above formula I the designated alkenyloxy and halo-alkenyloxy groups as well as the alkyl moieties of the designated (alkylthio)3arbonyl, alkanoylamino and phenyl-alkyl groups may be branched or straight-chained. Examples of such moieties and groups are methyl, ethyl, propyl, isopropyl, n-, i~, sec - and tert. -butyl, allyloxy, methallyloxy, 0-chloro- allyloxy arid γ-chloro-allyloxy .

The compounds of the present invention may be prepared by reacting the corresponding halide of the foi*mula II (II) -wherein x represents a halogen atom, with the corresponding phenol of the formula III in the presence of an acid binding agent Preferably equimolar quantities of the starting materials are employed for the above reaction, but an excess of either of the reactants may be used. Preferably X represents a chlorine or bromine atom.

The above reaction is performed with mixtures of the geometrical isomers of the reactive allylic halide of the formula II and the desired phenol and is carried out in a solvent which is inert under the conditions of reaction such as 1,2- dimethoxyethane, tetrahydrofuran^, dioxane, dimethylfprmamide, - dimethyljsulfoxide, sulfolane or a dialkyljether preferably, in 1, 2-dimethoxyethane ,and with the slow addition of preferably one equivalent of an acid acceptor such as an alkali-metal or alkaline-earth-metal hydroxide or carbonate, or of an alkali- metal alkoxide or. hydride. The addition of the acid binding ♦..agent is effected with stirring at room temperature and optionally with subsequent warming. The isolation of the ter- pene aryl ether then takes place by known techniques. Preferred alkali-metals are potassium and sodium and the preferred alkaline-earth-metal is calcium.

According to a second process the compounds of the formula I, wherein represents an alkenyloxy or halo-alkenyloxy group and R^ represents a hydrogen atom) can be prepared by reacting the corresponding compound of the ormula IVa with a compound of the formula Va R'3 - X (Va) wherein R'^ represents an alkenyl or halo-alkenyl grou containing from 2 to 4 carbon atoms, and X represents a halogen atom, or the compounds of formula I, wherein j represents a hydrogen atom and ^ represents a propargyl-oxy group, can be prepared by reacting the corresponding compound of the formula IVb (IVb) with a compound of the formula Vb CH s C - CH2 - X (Vb) wherein X represents a halogen atom, the reaction being conducted in the presence of an acid binding agent.

Again as a halogen atom X is preferably chlorine or bomine.

Suitable acid binding agents include tertiary amines and alkali-metal carbonates and hydroxides.

According to a third process the compounds of the formula I wherein and Z2 together represent an oxygen bridge between the carbon atoms to which they are attached may be prepared by reacting the corresponding compound of the formula la with an epoxidising agent in the presence of an inert solvent.

This epoxidisation reaction is preferably carried out with cool-ing in an inert solvent medium such as a chlorinated hydrocarbon, with an epoxidising agent, for example a peracid. Using one mol of a peracid, as a result of the steric factor the desired 6,7 epoxy derivative is formed predominantly. If 2 mol or more of the epoxidising agents is used, 2,3; 6,7 diepoxy derivatives tend to be obtained and this is to be avoided. The 6,7 epoxy derivatives can also be obtained with Ef-bromosuccinimide in a mixture of water with a solvent such as tetrahydrofuran, 1 ,2-dlmethoxyethane, dioxane, or tert.butanol in homogeneous or heterogeneous phase and subsequent treatment of the obtained intermediary bromohydrln with an alkaline agent such as an alkali-metal carbonate, alkali-metal hydroxide or an alkali-metal alkoxlde. Among alkali-metals particularly sodium and potassium are to be understood.

By the term peracid, there is to be understood preferably low alkane peracids with 1-6 carbon atoms, e.g. peracetic acid, as well as aromatic peracids such as per-benzoic acid, monoperphthallc acid, and particularly m-chloroperbenzoic acid.

In the manufacture of the compounds of the formula I according to the above processes, as a result of the use of mixtures of the various geometrical isomers of the starting ma teriale, all possible geometrical isomers of the compounds of the formula I are prepared. The compounds herein described and claimed are accordingly to be understood as being in the form of mixtures of the possible geometrical isomers thereof.

The compounds of formula I are suitable for combatting most varied of animal and vegetable pests, particularly fo combatting insects. In oontrast to most previously known insecticides which rapidly kill, paralyse or drive away the animals and which work as contact or ingestion poisons, the active substances of formula I influence development.

Thus in insects for example, moulting (in Hemimetabola) disturbedf. of the transformation to the imago (in Holometabola) is/ The succession of generations is interrupted and the animals are thus indirectly killed off. For warm-blooded animals the compounds of formula I are practically non-toxic. As well as this, these compounds are easily decomposed and accumulation is accord ingly not possible.

The new terpenoid aryjjethers can be used above all for combating the following plant, stored product and hygiene pests: against insects of the order and families: Orthoptera Acrididae (e.g. locusts, Schi stocerca) Gryllidae (e.g. Acheta, Gryllus) Blattidae (e.g. Blattella germanica, Periplaneta americana, Nauphoeta cinera) Isoptera Kalotermitidae (e.g. Kalotermes) Hemiptera Miridae_ (e.g. Distantiella) Piesmidae (e.g. Piesma) Lygaeidae (e.g. Lygus) Pyrrhocoridae (e.g. Dysdercus) Pentatomidae (e.g. Eurydema) Cimicidae (e.g. Cimex) Reduviidae (e.g. Rhodnius) Jassidae (e.g. Empoasca) Erio.somatidae (e.g. Eriosoma) Lecaniidae (e.g. Coccus) Coleoptera Carbidae (e.g. Carabus) Elateridae (e.g. Agriotes) Coccinellidae (e.g. Epilachna) Tenebrionidae (e.g. Tribolium, Tenebrio) e mes ae .g. ermestes, nthrenus, Atfcagenus) Cucujidae . g. Oryzaephilus) Chrysomelidae . g. Leptinotarsa, Melasoma, Phyllotreta) Curculionidae . g. Sitona, Anthonomus) Scolytidae .g. Scolytus) Scarabaeidae .g. Melolontha) Lepidoptera Pyralidae .g. Diatraea) Phyticidae . g. Anagasta) Pyraustidae .g. Pyralis) Crambidae .g. Chilo) Tortricidae .g. Pandemis) Galleriidae .g. Galleria) Lyonetiidae .g. Lyonetia) Yponomeuti'dae .g. Hyponomeuta) Pieridae" .g. Pieris) Plutallidae .g. Plutella) Lymantriidae .g. Lymantria) Noctuidae .g. Spodoptera) Diptera Culicidae .g. Aedes) Simuliidae .g. Simulium) Tipulidae .g. Chironomus) . in accordance with the foregoing the present invention also provides a method of combatting insects, which comprises applying to said insects or to their locus or habitat a compound of the formula I as described herein, as well as a method of combatting the deleterious attack of agricultural .crops, stored goods or commercially reared livestock by insects, which comprises treating said crops, stored goods or livestock with a compound of the formula I as desoribed herein.

The compounds of the formula I can be used alone or together with suitable carriers and/or additive materials. Suitable carriers and additive materials can be solid or liquid and correspond to the customary materials used in formulation technique, e.g. natural or regenerated materials, solvents, dispersing agents, wetting agents, adhesives, thickeners, binders and/or fertilisers.

The manufacture of agents according to the invention takes place in known fashion by intimate mixing and/or milling of active substances of formula I with suitable carriers, optionally with the addition of dispersing agents or solvents inert to the active substance. The active substances can be present and be used in the following use forms: Solid use forms: dusting agents, spreading agents, granulates, coated granules, impregnated granules and. omogeneous granules.

. Liquid use forms:' a) Active substance concentrates dispersible ·. in v/ater: v/ettable powders, pastes, emulsions; ) solutions. ?or the manufacture of solid use forms (dusting agents, spreading agents) the active substances are mixed with solid carriers. As carriers there are , for example, kaolin," talcum, attapulginb C(LU bolus, loess, chalk, limestone, limestone grave1 , ao?cfoloy , J dolomite, diato aceous earth, precipitated silica, alkaline cates (feldspars and mica) , calcium and magnesium sulphates, magnesium oxide, ground plastic^ materials, fertilisers such as ammonium sulphate, ammonium phosphate, ammonium nitrate, urea, ground vegetable products such as crop flour, baric flour wood flour, nutshell flour, cellulose powder, residues from plant extraction, active carbon etc. , each being usable per se, or in admixture with others.

Granulates can be made very easily by dissolving an active substance according to Formula I in an organic solvent medium, applying the solution so obtained to a granulated material such as attapulgite, SiC^, lime, bentonite etc. and then evaporating the organic solvent medium' again.

Polymeric granulates can also be made by mixing the active substance of Formula I with polymerisable compounds (urea/formaldehyde, dicyandiamide/formaldehyde , mela ine/ formaldehyde or others) and then carrying out a careful polymerisation which does not affect the active substance, and wherein during the gel-formin stage, granulation is carried out. It is more favourable to impregnate preformed porous polymer granules (urea/formaldehyde, polyacrylonitrile , polyester and others) with a given surface area and favourably predetermined adsorption/desorption ratio with the active substance, e.g. in the form of a solution (in a low-boiling solvent) and then to remove the solvent. Such polymer granulates can be used in the form of icrogranulates of bulk density of preferably 300 to 600 g/litre with the aid of dusting apparatus. Dusting can be carried out over extended surfaces of useful plant cultures with the aid of aircraft.

Granulates can also be obtained by compacting the carrier material with the active material and additive materials and then br in These mixtures can furthermore contain additives stabilising the active substance and/or non-ionic, anion active or cation active materials, which, for example, improve the adherence, of the active substance to plants and plant parts (adhesives and glues) and or guarantee better penetration (wetting agents) or dispersability (dispersing agents).

The following substances may, for example, be used: Olein-lime mixtures, cellulose derivatives (methyl cellulose, carboxymethyl cellulose), hydroxyethyleneglycol ethers of mono- and dialkyl phenols with 5-15 ethylene oxide groups per molecule and 8-9 carbon atoms in the alkyl group, lignin*-. sulphonic acids, their alkali and alkaline earth salts, polyethylene glycol ethers (Carbowaxes) ,fatty alcohol poly-glycol ethers with 5-20 ethylene oxide groups per molecule and 8-18 carbon atoms in the fatty alcohol part, condensation products of ethylene oxide, propylene oxide; polyvinyl pyrrol-idone, polyvinyl alcohols, condensation products of urea -formaldehyde as well as latex products.

Active substance concentrates dispersible in water, i.e. wettable powders,, pastes and emulsion concentrates are materials which can be diluted with water to any desired concentration. They consist of active agent, carrier, optionally additives stabilising the active substance , surface active agents and anti-foa ing agents, and optionally solvents.

The wettable powders and pastes are obtained by mixing or and/milling to homogeneity the active substance with dispersing agents and powder form carriers in suitable apparatus.- As carriers ,' for example the materials mentioned above for solid use forms can be used. In some cases it is advantageous to use mixtures of various carriers. As dispersing agents there can be used, for example: condensation products of sulphonated naphthalene and sulphonated naphthalene derivatives with formaldehyde , condensation products of naphthalene or of naphthalene^sulphonic acids with phenol and formaldehyde, as well as alkali, ammonium and alkaline earth metal salts of di-t-butyl-naphthalene^ulphonic acids , fatty alcohol sulphates, such as salts of sulphonated hexadeCanols , heptadecan-ols , octadecanols and salts of sulphated fatty alcohol glycol ethers, the sodium salt of oleyl methyl tauride, di-tertiary acetylene glycols, dialkyldilauryl ammonium chloride and fatty acid alkali and alkaline earth salts.

As anti-foa ing agents, silicones may be used.

The active substances are so mixed with the above noted additives, milled ,. sieved and graded that for wettable powders the solid part has a particle size of 0.02 to 0.04- mm, and in the pastes does not exceed 0.03 mm. For the manufacture of emulsion concentrates and pastes dispersing agents as set forth in the preceding paragraphs are used, organic .solvents and water. As solvents, there are, for example, alcohols, benzene, xylenes, toluene, dimethyl sulphoxide and mineral oil fractions boiling in the range 120 to $50°C. The solvent medium must be practically odourless, non-phytotoxic and inert with respect to the active substances.

Furthermore , the agents according to the invention can be used in the form of solutions. For this, one or more active substances of Formula I is dissolved in suitable organic solvents, solvent mixes or water. As organic solvent there can be used aliphatic and aromatic hydrocarbons, their chlorinated derivatives, alkyl naphthalenes, mineral oils, alone or in admixture with one another.

The content of active substance in the agents noted above lies betweeno.02 and 9 #> but it is to be noted that in application from aircraft or b means of other suitable application devices, concentrations of up to 99. # or even pure active substance could be used.

The active substances of Formula I can, for example, be formulated as follows: Dusting agent: for the manufacture of an a) and b) 2 dusting agent, the following materials were used. a) 5 parts active substance 95 parts talcum b) 2 parts active substance 1 part highly disperse silica 97 parts, talcum. ' .

The active substances were mixed with the carrier materials and milled.

Granulate: for anufact ring a 5 granulate, the following materials were used: parts active substance 0.25 parts epichlorohyd in 0.25 parts cetyl polyglycol ether . Ο parts polyethylene glycol ("Carbowax" ) 1 parts kaolin (particle size 0.3-0.8 mm).

The active substance v/as mixed with epichlorohydrin and dissolved in 6 parts acetone, whereafter the polyethylene glycol and cetyl polyglycol ether v/ere added. The solution thus obtained was sprayed onto kaolin and the acetone then evaporated _in vacuo. manufacturing an a) 40 , and b) and ) ^/ the following components were used: ? a) 40 parts active substance parts ligninjsulphonic acid, sodium salt 1 part dibutyl^jiaphthalene^sulphonic acid, sodium salt 54 parts silica; ) 25 parts active substance 4.5 parts calcium lignosulphonate 1.9 parts champagne chalk-hydroxyethyl cellulose mixture (1:1) 1.5 parts sodium dibutyl^nap t alene^sulp onate 19.5 parts silica 19.5 parts champagne chalk 28.1 parts kaolin. c) 25 parts active substance 2.5 parts isooctylphenoxy-polyoxyethylene-ethanol 1.7 parts champagne chalk-hydroxyethyl cellulose mix (1:1) 8.5 parts sodium aluminium silicate 16.5 parts kieselguhr 46 parts kaolin. d) 10 parts active substance 3 parts mixture of sodium salts of fatty alcohol sulphates parts naphthalene^jsulphonic acid formaldehyde condensate 82 parts kaolin.

The active substances were intimately mixed in suitable mixers with the additive materials and milled on suitable mills and rolls. Wettable powders wore obtained which could be diluted with water to suspensions of any desired concentration. 3raulsifiable concentrate: for manufacturing an a) 10# and b) 25^ emulsif able concentrate, the following materials were used: a) 10 parts active substance, 3. parts epoxidised vegetable oil, .4 parts of a combination emulsifier consisting of fatty alcohol polyglycol ethers and calcium alkyl~ aryl^sulphonates 0 parts dimethylfor amide 43.2 parts xylene. b) 25 parts active substance acid ester 2.5 parts epoxidised vegetable oil parts of an alkyl^aryl^ulphonate-fatty alcohol polyglycol ether mixture parts dimethylformamide 57-5 parts xylene.

Emulsions of any desired concentratio could be made from these concentrations by dilution with water.

Spraying agent: for making a 5 spraying agent the following components were used: · parts active substance 1 part epichlorohydrin 94 parts petrol (boiling range 160-190°C).

The materials described can also be mixed with other biocidally active substances or agents. Thus, the new agents can contain, apart from the noted compounds of general formula I, for -example, insecticides, fungicides, bactericides, fungistatic agents, bacteriostatic agents, nematocides or herbicides for broadening the spectrum of activity.

In accordance with the foregoing the present invention also provides an insecticidal composition comprising a compound of the formula I as herein described together with a solid or gether with a liquid diluent or carrier therefor and one or more surface active agents.

The following examples will serve to illustrate the manufacture of the compounds of the formula I.

Example 1 21.7 g l-bromo-3J 7-dimethyl-2> 6-octadiene was added to a solution of 15.2 g 3-propargyloxypher.Ol. (boiling point 84-85°/ 0, 02 torr nD : 1. 5640 ) in 150 ml pure 1, 2-dimethoxyethane, and immediately thereafter with stirring at 20 - 22°C a solution of 6. 4 g 85 % potassium hydroxide in 100 ml absolute ethanol was added dropwise. The addition of potassium hydroxide solution (lasting about 8 hours) was so regulated that the reaction mixture always remained weakly alkaline (pH about 8-9) · After the addition of the base the mixture was stirred further for 16 hours at room temperature and then warmed for one hour to 70°C and thereafter cooled and filtered from the precipitated potassium bromide. The filtrate was reduced to about 0 ml, taken up in a diethyl ether hexane mixture ( 1 : 4 ) washed 3 times with 30 ml 10 % aqueous potassium hydroxide and then washed neutral with water. The organic phase was dried over sodium sulphate and the solvent distilled off in vacuum. The remaining 1 ( 3-propargyloxy-phenoxy) -3 7-dimethyl-2, 6-octadiene was purified by chromatography on silica gel (activity III) with an ether hexane mixture ( 1 : 5 ) 20 : 1. 5326. This eth 'er can also be purified by high vacuum distillation.

Example 2 To a solution of 1^ .6 g 7-dimethyl-2, 6-nonadienyl- 1-oxy) benzophe one ( ^ : 1 .5763 ) in 160 ml dichloromethane there was added at -2 to 0° within six hours a solution of 8 .6 g 85$ 3-chloroperbenzoic acid in 90 ml dichloromethane dropwise. After a further three hours stirring at 0 to 5° the reaction mixture was diluted with ether, the solution repeatedly-washed with ice-cold 10$ aqueous caustic potash and then washed neutral with water. After drying the organic phase over sodium sulphate the solvent was distilled off in vacuum and the remaining 4- (6 , 7-epoxy-3 » 7-dimethyl-2-nonenyl-1-oxy) benzophenone chromatographically purified on silica gel with ether hexane The 4- (3 » 7-dimethyl-2 , 6-nonadienyl-1-oxy)benzophenone used as a starting product can be manufactured .in the following way: a solution of 6 .3 s. about 90 potassium hydroxide in a 100 ml absolute ethanol were added dropwise over a period of 7 hours to a solution of 23 .2 g 1~bromo-3 > 7-dimethyl-2 , 6-nonadiene and 19 .8 g 4-hydroxybenzophenone in 160 ml 1 , 2-dimethoxyethane, so that the reaction mixture always showed an alkaline reaction and stirring was then continued for 14 hours at room temperature. For finishing, the precipitated potassium bromide was filtered off, the filtrate reduced, the residue taken up in 200 ml ether, washed four times wit ice-cold 10$ caustic potash and then washed neutral with water. After drying the ether solution over sodium sulphate the solvent was removed in vacuum and the residue purified by chromatography on silica gel (ether hexane 1 : 3 ) whereby the 4- (3 j 7-dimethyl-2 , 6-nonadienyl-1-oxy) benzophenone was obtained, n-. : 1 .5673 .

The compounds in the following table were produced analogously to examples 1 and 2: [in the table, (-C-C-) represents an additional carbon-carbon bond and (-0-) represent an oxygen bridge]. 92j-2 The following examples illustrate the insecticidal prope of the compounds according to the present invention: Example 3 larvae of Dysdercus fasciatus, which were 8-10 days before the adult moult, were topically treated with acetonic active substance solutions. The test animals were then kept at 28°C and 80-90 relative humidity. As food, the Dysdercus fasciatus larvae had groats from preswollen cotton seeds.

After about 10 days, i.e. as soon as the control animals had completed their adult moult, the test animals were evaluated. Apart from normal adults and dead larvae special forms were to be found such as extra larvae (larvae with an additional larval skin) and adultoids (adults with larval features). In the special types it is a question of non-viable stages of development which are not to be found in the normal cycle of development.

From the following table the number of animals is evident which were to be found in each of the various development stages at the various concentrations given: A = normal adults B = extra larvae C = adultoids D = dead larvae.

Example 4 In each test 10 fresh pupae of Dermestes lardarius were topically treated with solutions of active substance in acetone. The pupae were then kept at 28° and 80-90 % relative humidity.

After about 10 days, i.e. as soon as the control animals had left the pupal casing as imagines, the test animals were evaluated; as well as normal adults and dead pupae adultoids (adults with larval characteristics) were found.

The adultoids were not viable stages of development and they are not to be found in the normal cycle of development.

A = normal adults C = adultoids D = dead pupae.

Amount of Derrnestes Lardarius Active SubA C D stance in 7 1- ( 4-Benzyl -phenoxy)-6i 7--epoxy-3, 7-dimethy1-2- 5 10 -octene l-[4-(2-Propen-l¾xy ) - -phenox J-6, 7-epoxy-3, 7- 5 9 1 -dime hyl-2-octene 0.5 10 1- (3-Propargyloxy -phenoxy)- -3, 7-dimethyl-2, 6-octadiene 5 3 7 C o n t r o l - 10 - - Example 5 In each case 10 fresh pupae of Tenebrio molitor were topically treated with active subsgance solutions in acetone. The pupae were then kept at 28° and 80-90 % relative humidity. After about 10 days, i.e. as soon as the control animals had left pupal skin as imagines, the test animals were evaluated. As well as normal adults and dead pupae, adultoids were found (adults with larval features) .

The adultoids were not viable stages of development and they are not to be found in the normal cycle of development.

A = normal adults C = adultoids D = dead pupae Example 6 fresh pupae each of Leptinotarsa decemlineata were topically treated with solutions of active substance in acetone. The pupae were then kept at 28° and 80-90 % relative humidity.

After about 10 days i.e. as soon as the control animals had left the pupal casing as imagines, the test animals were evaluated. As well as normal adults and dead pupae, adultoids. were found (adults with larval features). In the case of adultoids they are not viable stages of development and are not to be foun.d in the normal cycle of development.

A = normal adults C = adultoids D = dead pupae

Claims (1)

1. What we claim Compounds of the formula I wherein and Z2 together represent an additional bond or an oxygen bridge between the carbon atoms to which they are and independently of each represent a methyl or ethyl and either represents an alkenyloxy or group each containing from 2 to 4 carbon or alkanoylamino group each containing from 2 to carbon a benzyloxy or benzoyl or a group having from 1 to carbon atoms in the alkyl while R 4 represents a hydrogen or R represents hydrogen while 3 R represents a propargyloxy Compounds as claimed in claim 1 wherein R represents an 3 phenoxy or h group and R represents a hydrogen Compounds as claimed in claim 1 wherein represents a hydrogen atom and represents a propargyl 879 21 me 30 lox Process for the of compounds of the formula I as defined in Claim 1 which comprises reacting the corresponding halide of the ormula wherein represents a halogen the corresponding phenol of the formula III in the presence of an acid binding of compounds of the I as in Claim wherein represents an or group and represents a hydrogen which comprises reacting the corresponding a compound o the ormula Va X wherein represents an alkenyl group containing from 2 to 4 carbon and X represents a halogen Process for production compounds of the formula 1 as in Claim wherein represents a hydrogen atom represents a propargyloxy which reactin the corresponding compound of the b compound of the formula X wherein X represents a halogen the reaction being conducted in the presence of an acid binding Process for the production of compounds of the formula I as defined in claim 1 wherein and together represent an oxygen between the carbon atoms to which they are attached which comprises reacting the corresponding compound of the formula with an epoxidising agent in the presence of an inert 31 30 Process as claimed in any one of claims o substantially as described with reference to the accompanying 32 An insecticidal composition comprising a compound as claimed in any one of claims 1 to together with a solid or diluent or carrier or together with a liquid diluent or carrier therefor and one or more surface active A method of combatting which comprises applying to said insects or to their locus or habitat a 26 compound as claimed in any one of claims 1 insufficientOCRQuality