HU185218B - Process for producing new lactolalcohol-cyclopropane-carboxylate derivatives - Google Patents

Abstract

The present invention relates to novel lactol alcohol cyclopropanecarboxylate derivatives of the optically active and racemic formula I, wherein R and R1 are the same or different and are hydrogen or halogen, straight or branched lower alkyl, or lower alkoxycarbonyl, \ t X is a halogen atom or a phenoxy or phenylthio group which is mono- or polysubstituted with a halogen, lower alkyl or alkoxy group, phenyl, nitro or di (lower alkyl) amino group; ---- binding line a-spacing,., és binding /? - spacing, and α-and / or-7 spacing of the binding line such that: a) optically active or racemic lactone alcohol 11 cyclopropanecarboxylate derivatives are reduced in complex, aprotic organic solvents with complex metal hydrides, or b) opti of formula III reactive or racemic lactol-O-alkyl derivatives are reacted in an aprotic, inert, organic solvent in the presence of a base with optically active or racemic chrysanthemic acid derivatives of formula (IV) followed by acylated lactol-O-alkyl of the optically active or racemic formula VII. derivatives are hydrolyzed in an acid medium. -1-

Description

The present invention relates to novel optically active or racemic lactol alcohol cyclopropanecarboxylate derivatives of formula I.

In the general formula 1

R and R ¹ are the same or different and are hydrogen or halogen, straight or branched lower alkyl, one of which may also be lower alkoxycarbonyl,

X is a halogen atom or a phenoxy or phenylthio group, mono- or polysubstituted with a halogen atom, a lower alkyl or alkoxy group, a phenyl, nitro or di (lower alkylamino group); space, ◄ bond line / J-line, ~ bond line / (- and / or α-space). Natural pyrethrins are known to have outstanding biological activity as an insecticidal agent. Their insecticidal activity is demonstrated even at very low concentrations. but they are virtually atoxic to mammals, and their ancillary effects, such as knock-down and repellant effects, are also excellent, but the compounds have been used as insecticides for about 100 years, but have not developed resistance. as opposed to insects.The natural pyrethrons are therefore all in the immediate human environment and can be used in agriculture and are very beneficial to the environment.

Natural pyrethrins are mainly obtained from oil extracted from the flower of the Chrysanthemum cinerariaefolium plant, which is produced in tropical countries. In addition to pyrethrins, the extract contains a number of other inactive compounds (such as tombs, steroids, flavonoids, chlorophyll) which can only be purified by lengthy chromatography. It is also difficult to separate the individual pyrethrins in pure form because their molecules behave very physically and chemically similar to one another. Epimerization usually occurs during their chromatographic separation.

However, in some cases this separation was successful and it is known that the potency and stability of the individual components vary considerably. For example, pyrethrin I and cinerin are more potent than jasmine I (J. Science of Food and Agriculture, Vol. 3, 260, 1962), while cinerin 1 and jasmine I are much more stable than pyrethrin I ( Pyrethrum Post, Vol 9, 17. [1968]). Synthetic production of pyrethrins and related derivatives (pyrethroids) has long been a demand. The material synthesized closest to the natural pyrethrins is bioaliethrin and Sbioallethrin (compound of formula V). The former product is the racemic alletrolone ester of d- (+) -trans-trans-tartaric acid, while the latter product is also resolved by alcohol (+), a right-turning alletrolone.

For example, U.S. Patent No. 7,413,401 is known. from the Dutch patent application that the insecticidal activity of S-bioalletrin is several times higher than that of bioalletrin measured in the same way.

Some solutions are known for the total synthesis of racemic "natural" pyrethrins. These are summarized in Chapter 4 of Pyrethrum the Natural Insecticide, edited by J. E. Casida (Aeademic Press, N. Y., London, 1973). v

Up to now, the synthesis of optically active "natural" pyrethrins in the same configuration as the natural has so far been conceptually possible, namely the resolution of the racemic (±) -retrolone followed by acylation of the corresponding enantiomer with d- (4) -trans-chrysanthemic acid.

Resolution of racemic (±) -retrolones is a very difficult and extremely uneconomic process. For example, resolution by appropriate semicarbazidone is known (J. Org. Chem. 29, 5225 (1964)).

According to methods known so far for the preparation of pyrethrins, racemic retrolones (alcohol components of pyrethrins) have been acylated with chrysanthemic acid derivatives. During the preparation of the racemic retrolones, the hydroxyl group to be acylated must subsequently be protected and then, after formation of the retrolone molecule, protected. should be removed before acylation. However, retrolones are decomposable compounds (Chem. And Ind., 1142, [1966]) in which the deprotection and deprotection causes significant degradation.

Surprisingly, it has now been found that the novel lactol-alcohol-cyclopropanecarboxylate derivatives of the general formula I according to the invention are very useful as intermediates in the synthesis of pyrethrins and their analogs. This is because the compounds can be used to form the carbon skeleton of pyrethroids. Removal of the halogen substituent at X at the compounds thus obtained, for example by dehydrohalogenation, affords a derivative containing an oxymethylene group which provides the desired pyrethroid derivative by oxidative rearrangement.

The novel lactol alcohol cyclopropanecarboxylate derivatives of the formula I themselves have insecticidal activity.

The novel optically active or racemic lactol alcohol cyclopropanecarboxylate derivatives of formula I are prepared according to the invention by:

(a) optically active or lactone alcohol cyclopropanecarboxylate derivatives of the general formula (II) - wherein R, R ', X, -----, α, and - are as defined in complex inert aprotic solvents as defined above, or

b) optically active or racemic needle bicyclic lactol-O-alkyl derivatives of the general formula III wherein X, a ------, ◄ cs a - have the same meaning as defined above and R ^{2 has from} 1 to 6 carbon atoms optionally with halogen. represents a substituted straight or branched alkyl group with an aprotic, inert, organic solvent optically active or racemic derivative of the chrysanthemic acid of formula IV wherein R, R 'and the ~

185 218 has the same meaning as above and Z represents a halogen atom or a mesyl, tosyl, imidazolyl or a group of formula - Ό-CO-Q, wherein Q is a straight or branched alkyl optionally substituted by halogen. , an aryl, aryloxy, aralkyl or aralkyloxy group, or Z is a group of formula VI in which R, R ¹ and the - bond are as defined above - are reacted in the presence of a base and the resulting optically active or racemic The acylated lactol-O-alkyl derivatives of formula VII - wherein R, R ¹ , R ² , X, -----, α and - are defined by hydrolysis in the above-described acidic medium.

Suitable aprotic organic solvents for use in the process of the present invention include aromatic hydrocarbons such as benzene or toluene, ether-type solvents such as tetrahydrofuran or dioxane, halogenated hydrocarbons such as carbon tetrachloride. , or dichloroethane. However, it is also possible to use other solvents, such as dimethylformamide, as an aprotic, inert organic solvent. Mixtures of the above solvents may also be used.

In the process according to the invention, complex aluminum hydrides such as, for example, complex femhydrides may be advantageously used. such as diisobutylaluminum hydride, lithium tri- (lower alkoxyaluminum hydride), which is the same as the known reducing agent marketed under the trademark "Red-A1 ^R ". Examples include lithium triisobloxyaluminium hydride, and the reduction is preferably carried out at -100 to -20 ° C.

The reduction according to process variant (a) is very preferably carried out by reducing the compounds of the formula II with diisobutylaluminum hydride at -78 ° C in a mixture of methylene chloride-toluene or also at -78 ° C in a tetrahydrofuran-toluene mixture.

In the process variant b) of the invention, the base may be inorganic or organic bases. Preferably, however, organic tertiary amine-type bases such as triethylamine, pyridine, imidazole and the like are preferred. Optionally, the organic base employed may also serve as an aprotic, inert organic solvent, either alone or in a mixture with any of the solvents indicated above.

The acylated lactol-O-alkyl derivatives of formula VII obtained in process step b) are hydrolyzed under acidic conditions to give the lactol alcohol cyclopropanecarboxylate derivatives of formula I. The hydrolysis may conveniently be carried out with an aqueous solution of a lower alkanecarboxylic acid, or may be carried out using a mixture of a water-miscible organic solvent and an aqueous solution of a mineral acid. An example of the latter is a 1: 1 solution of tetrahydrofuran-0.1N hydrochloric acid.

The reactions of the invention can be carried out within a wide range of temperatures. However, process variant (a) is conveniently carried out at low temperature, while reaction (b) may be carried out at room temperature or at slightly elevated or reduced temperature.

The aryl moiety of the aryl, aryloxy, aralkyl and aralkyloxy groups described herein is an aromatic group having 6 to 10 carbon atoms, preferably phenyl or naphthyl, which may be substituted or is preferably substituted as defined in X. The alkyl portion of the alkyl, alkoxy, aralkyl and aralkyloxy groups may be C 1 -C 10, preferably C 1 -C 4, straight or branched alkyl.

The lower alkyl or alkoxy radicals may have from 1 to 4 carbon atoms and may be straight or branched.

Preferred C 1-4 alkyl groups are methyl, ethyl, n- and i-propyl, η, chair and tert-butyl.

By halogen is meant fluorine, chlorine, bromine and iodine. Preferred representatives of these are chlorine and bromine.

The optically active or racemic compounds of formula II used as starting materials were subjected to selective halogenation of 3,3aa, 4,5,6,6aa-hexahydro-2-oxo-4a-hydroxymethyl-5β-hydroxy-2H-cyclopentanojb] furan to give 4a. the halomethyl derivative may, if desired, be converted to the corresponding 4a-phenoxy or 4a-phenylthio derivative and then acylated with an optically active or racemic chrysanalamic acid derivative of formula IV.

The optically active or racemic bicyclic lacto-O-alkyl derivatives of the general formula 1 used as starting materials are obtained if the 3,3an, 4,5,6,6a-hexahydro-2-oxo-4a-halomethyl (or -phenoxymethyl) or -phenylthiomethyl -) -? - hydroxy-2H-cyclopentano [b] furan derivatives, e.g. Using the reducing agents mentioned in process variant a), the corresponding 2-hydroxy derivative is reduced to a coke and reacted with a C 1 -C 6 optionally halogen-substituted straight or branched alkanol in the presence of a catalytic amount of acid.

The insecticidal activity of the optically active and racemic lactol alcohol cyclopropanecarboxylal derivatives of the formula I according to the invention was tested on the Musea domestica test insect at a dose of 0.005 mg / insect. The results are shown in the following table:

R ' R X KD ₅ , (min) Mortality 24 hours (%) meti'- methyl- chlorine 38 65 meti'- methyl- bromide- 40 70 methyl- methyl- phenylthio 45 68 meti'- methyl- phenoxy 70 55 chlorine- chlorine- chlorine- 66 70 chlorine- chlorine- bromide- 100 83

218

R ' R X Volume ₅₀ (min) Mortality 24 hours (%) bromide- bromide- bromide- 100 85 fluorine- fluorine- chlorine- 28 60 chlorine- chlorine- phenylthio 60 60 bromide- bromide- phenoxy 80 75

The compounds of formula I may also be used as active ingredients in insecticidal compositions because of their insecticidal activity. In this case, the active compounds of the formula I are formulated into insecticidal compositions using diluents, fillers and / or other formulation auxiliaries customary in the preparation of insecticidal compositions.

Diluents, fillers and / or formulation auxiliaries may be solid, liquid and / or gaseous materials. Examples of solids include natural and artificial rock grinds, organic and inorganic granules. Liquid materials are various solvents and solvent mixtures. Gaseous materials are preferably aerosol propellants liquefied under pressure.

In addition, the insecticidal compositions may also contain coloring agents, surfactants, perfumes and / or flavoring agents.

Further details of the invention are illustrated by the following non-limiting examples.

Example 1

3,3aa - 4,5,6,6aaHexahydro - 2 - hydroxy - 4a bromomethyl - 2H - cyclopentanojb] furan - 5β - yl (+) - trans - chrysanthemum

Into a four-necked flask equipped with a 100 ml stirrer, a plunger thermometer, a metering funnel, were charged 5.87 g (15 mmol) of 3.3a, 4,5,6,6a-hexahydro-2-oxo-4a-bromomethyl-2H-cyclopenlano [ b] furan-5β-yl - (+) - trans-chrysanthemate in 20 ml of anhydrous tetrahydrofuran.

The solution was cooled to -70 ° C and a solution of 2.6 g (18 mmol) of diisobutylaluminum hydride in 20 ml of anhydrous toluene was added dropwise at this temperature.

The solution is stirred at -70 to -78 [deg.] C. for half an hour and then 15 ml of saturated sodium chloride solution are added. The dry ice-acetone bath was then removed and the reaction temperature was allowed to rise to room temperature. A further 30 ml of saturated sodium chloride solution was added at 10 to 20 ° C, and the suspension was stirred for another half hour.

The mixture was filtered, and the filtered aluminum salts were washed with ethyl acetate (3 x 50 mL). The filtrates were combined, the layers separated and the aqueous layer extracted with ethyl acetate (3 x 60 mL). The organic layers were combined, dried over anhydrous sodium sulfate, filtered and concentrated under reduced pressure. 3.56 g (92.1%) of the title compound are obtained.

Physico-chemical characteristics of the product:

_Rf: 1 mixture of petroleum ether-ethyl acetate: 0.51 1

NMR (CDCl 3): δ = 5.51 (m, 1H) 4.8 (m, 1H) 4.3 (m, 1H) 3.42 (d, 2H) 1.58 (s, 6H) 1 , 23 and 1.08 (s + s, 3H + 3H) ppm.

In analogy to the above, the following compounds can be prepared:

3,3aa, 4,5,6,6aa - Hexahydro-2-hydroxy-4a-chloromethyl-2H-cyclopentano [b] furan-5β-yl - (+)

trans - chrysanthemum

R _f = 0.505 with petroleum ether / ethyl acetate 1: 1

3,3aa, 4,5,6,6aa - Hexahydro-2-hydroxy-4a-phenylthiomethyl-2H-cyclopentanofbjfuran-5β-yl (+) - trans-chrysanthemum

_Rf -0.36 2: 1 mixture of petroleum ether and ethyl acetate =

3,3aa, 4,5,6,6a a - Hexahydro - 2 - hydroxy - 4a

- chloromethyl-2H-cyclopentano [b] furan-5β-yl- [3- (2,2-dichloro-vinyl) -2,2-dimethyl-cyclopropane (1)

R, trans -carboxylal]

R f = 0.41 1: 1 petroleum ether / ethyl acetate NMR (CDCl 3): δ = 5.4-5.7 (m, 2H), 4.95 (m, 1H) 4.31 (m, 1H) , 3.45 (d, 2H), 1.3 and 1.2 (s + s, 3H + 3H) ppm.

3,3a, 4,5,6,6aa-hexahydro-2-hydroxy-4a-brómmelil-2H-cyclopentane [b] furan ^ -yl [3- (2,2-dibromo-vinyl) -2,2-dimethyl- (1R, cis) carboxylate].

_Rf = 0.43 (l: 1 mixture of petroleum ether and ethyl acetate =)

NMR (CDCl 3): δ = 6.24 (d, 1H), 5.53 (m, 1H) 4.92 (m. 1H), 4.3 (m, 1H), 3.43 (d, 2H) ), 1.3 and 1.2 (s + s), (3H + 3H) ppm.

3,3au, 4,5,6,6aa - Hexahydro-2-hydroxy-4a-phenylthiomethyl-2H-cyclopentanofibrofuran-5β-yl [3- (2,2-dibromo-vinyl) -2,2-dimethyl- (IR, cis) carboxylate],

_Rf = 0.28 (2: 1 mixture of petroleum ether and ethyl acetate =)

Example 2

3,3aa, 4,5,6,6aa - Hexahydro-2-hydroxy-4a-bromomethyl-2H-cyclopentanojbjfuran-5β-yl (+)

trans - chrysanthemum

The procedure described in Example I was repeated except that diisobutylaluminum hydride was added in the form of a 10% solution in anhydrous toluene instead of 18 mmol of sodium bis (2-methoxyethoxy) anhymium hybrid and the reaction was carried out at -20 ° C. .

This gave 3.1 g (80.2%) of the title compound. The crude product thus obtained was purified by column chromatography. 1: 1 benzene: ethyl acetate. The product obtained has the same physico-chemical characteristics as in Example I.

Example 3

3,3a, 4,5.6,6aa ~ 2,5pdihidroxi-hexahydro-2H ~ ~ 4abrómmetil cyclopentano [b] furan

Dried, with stirrer. with protruding thermometer and

Into a 185 218 four-necked flask with a transfer funnel was placed 2.5 g (10.68 mmol) of 3,3aa, 4,5,6,6a-hexahydro-2-oxo-4a-bromomethyl-5β-hydroxy-2H-cyclopentano [ b] furan side with 40 ml of anhydrous methylene chloride. The flask was purged with nitrogen and cooled to -78 ° C.

While stirring at -70 to -78 ° C, a solution of 4.55 g (32 mmol) of diisobutylaluminum hydride in 20 ml of anhydrous toluene was added dropwise to the solution over 20 minutes. After stirring for a further half an hour, 10 ml of a saturated sodium chloride solution were added and the cooling bath was allowed to rise to room temperature. An additional 30 mL of saturated sodium chloride solution was added and the suspension was stirred for half an hour.

The precipitated salts were then filtered through a glass filter and washed with ethyl acetate (3 x 50 mL). The filtrates were combined and the phases were separated. The aqueous phase was extracted with ethyl acetate (3 x 50 mL). The organic phases are combined, dried over sodium sulfate, filtered and concentrated under reduced pressure.

2.45 g (97%) of the title compound are obtained.

Physico-chemical characteristics of the product:

_Rf = 0.2 (2: 1 ethyl acetate: petroleum ether digested)

NMR (CDCl 3): δ = 5.5 (m, 1H) 4.1-4.5 (m, 2H) 3.4 (d, 2H) ppm.

Example 4

, 3,3a. 4,5,6,6av.-hexahydro-2-methoxy-4Z brómtnetil-5P-hydroxy-2H-cyclopentano [b] bores

2.37 g (10 mmol) of 3,3aaa, 4,5,6,6a-hexahydro-2,5? -Dihydroxy-4a-bromomethyl-2H-cyclopentano [b] furan are weighed into a 100 ml round bottom flask and dissolved in 15 ml of anhydrous methanol. To the solution was added 2 drops of 5% HCl in methanol at room temperature, the flask was fitted with a calcium chloride tube and the solution was stirred for half an hour.

The methanol is then removed under reduced pressure. The residue is taken up in 50 ml of ethyl acetate and washed with 10 ml of 2.5% sodium bicarbonate solution and 10 ml of saturated sodium chloride solution.

The organic phase is dried over sodium sulfate, filtered and concentrated under reduced pressure.

Yield: 2.45 g (98%).

Physico-chemical characteristics of the product:

R _f = 0.42 (2: 1 ethyl acetate / petroleum ether mixtures)

NMR (CDCl ₃ ): δ = 5.2 (m, 1H), 4.1-4.35 (m, 2H) 3.45 (d, 2H) 3.3 and 3.35 (s + s, 3H) ) ppm.

Example 5

3,3aa.4,5,6,6aa.-Hexahydro-2-meloxy-4a.-bromomethyl-2H-cyclopentano [b] furan (4'-yl) trans-trans-chrysanthemate

A 50 mL round bottom flask was charged with 2 g (7.9 mmol) of 3,3aaa, 4,5,6,6aaa-hexahydro-2-methoxy-4-bromomethyl-53-hydroxy-2H-cyclopentano [b] furan and dissolved in 5 mL in anhydrous pyridine. To the solution was added 1.64 g (8.7 mmol) of (+) - trans-chrysanthemic acid chloride at room temperature. After stirring at 60 ° C for 2 hours, excess pyridine was distilled off under reduced pressure. The residue was taken up in benzene (80 ml), extracted with 2.5% sodium bicarbonate (2 x 30 ml), brine (10 ml), dried over sodium sulfate, filtered and concentrated under reduced pressure. 3.02 g (92.1%) of the title compound are obtained.

Physico-chemical characteristics of the product:

R _f = 0.44 (1: 1 ethyl acetate / petroleum ether mixtures)

NMR (CDCl3): δ = 5.6 (m, 1H), 5.26 (m, 1H), 4.95 (m, 1H), 4.2 (m, 1H), 3.45 (d, 2H) ), 3.3 and 3.34 (s + s, 3H), 1.6 (s, 6H), 1.2 and 1.3 (s + s, 3H + 3H) ppm.

Example 6

3,3cx, 4,5,6,6aa-Hexahydro-2-hydroxy-4x-bromomethyl-2H-cyclopentanofb] furan-5β-yl (+) - trans-chrysanthemate is weighed into a 2.5 ml 3.3 ml round bottom flask, 4,5,6,6aa-Hexahydro-2-methoxy-4a-bromomethyl-2H-cyclopentano [b] furan 5-yl - (+) - trans-chrysanthemate and dissolved in 20 ml of 85% acetic acid. The solution was stirred for 48 hours at room temperature.

The reaction mixture was diluted with ether (100 mL) and washed with 5% sodium bicarbonate (6 x 50 mL).

The organic phase is dried over sodium sulfate, filtered and evaporated. The crude product is chromatographed on 100 g of silica gel with 2: 1 petroleum ether / ethyl acetate. The thin layer chromatographic analysis of the _Rf 0.51: proper (1: 1 mixture of petroleum ether-ethyl acetate) spot fractions were collected and concentrated under reduced pressure. This gave 1.5 g (62%) of the title compound. The product has the same physico-chemical constants as in Example 1.

The R _f values given in the examples were always measured on Merck Kieselgel 60 F ₂₅₄ , Art 5719 sheets.

Claims (14)

A process for the preparation of a novel optically active and racemic lactol alcohol cyclopropanecarboxylate derivative of formula (I): R and R 'are the same or different and are hydrogen or halogen, straight or branched lower alkyl, one of which may be lower alkoxycarbonyl, X is a halogen atom or a phenoxy or phenylthio group mono- or polysubstituted with a halogen atom, a lower alkyl or alkoxy group, a phenyl, nitro or di (lower alkyl) amino group; bond line a-space position. -5I 185,218 means the <b> J-position and the ~ -binding line are β- and / or α-positions, characterized in that a) (II) of formula in optically active or racemic laktonalkohol cyclopropanecarboxylate derivatives stem ⁵ - wherein R, R ', X and -----, ◄ and the ~ bond line are as defined above - in an inert aprotic organic in solvents by reduction with complex metal hydrides, or b) optically active or θ racemic lactol-O-alkyl derivatives of the formula (III) wherein X, a ------, the <and - bond are as defined above and R ^{2 is} a straight or branched alkyl group containing from 1 to 6 carbon atoms, optionally substituted with halogen, - optically active in aprotic, inert, organic solvents in the presence of a base or with racemic chrysanthemic acid derivatives of formula (IV) - wherein R, R ¹ and the - bond are as defined above and Z is halogen, _2Q or mesyl / tosyl, imidazolyl or a group of the formula -O-CO-Q, wherein Q is a linear or branched, optionally halogen-substituted alkyl or alkoxy group, an aryl, aryloxy, aralkyl or ₂₅ aralkyloxy group, or Z is a group of the general formula (VI) wherein R, R 'and the ~ bond line are as defined above -, and reacting the resulting optically active or racemic (VII) is acylated lactol derivative of _30-O-alkyl derivatives are - where R, R', R ^2, X, A --- ---, the and the bond is as defined above in an acidic medium. Process variant (a) according to claim 1, characterized in that the inert, aprotic organic solvent is aromatic hydrocarbons and / or ether-type solvents and / or halogenated hydrocarbons. 3. The process according to claim 2, wherein the inert aprotic organic solvent is toluene 40 and / or tetrahydrofuran and / or dichloromethane. The process variant of claim 1 a) and the method of claims 2-3. Process according to any one of claims, characterized in that ₄₅ is used minium hydride complex metal hydride complex ALU. 5. A method according to claim 4, characterized in that the reduction is a complex aluminum hydride _{in 50} is carried out using diisobutylaluminum hydride or sodium bis (2-methoxyethoxy) aluminum hydride. Process variant (b) according to claim 1, characterized in that the compounds of the formulas II and IV the reaction of R, R ¹ , R ² , X, a - and ◄ as defined in claim 1, 55 and Z is halogen - is carried out in pyridine. 7. The claim 1 process b) variant, characterized in that the resulting optically active or racemic formula VII acetylated lactol-O-alkyl stem ₆₀ derivatives: - wherein R, R ^1, R ^2, X, a--, hydrolysis of α and β as defined in claim 1 is carried out in aqueous acetic acid. The variant of process a) of claim 1 or the process of claim 5 2-5. A process according to any one of claims 1 to 4 for the preparation of 3,3aaa, 4,5,6,6a-hexahydro-2-hydroxy-4a-bromomethyl-2H-cyclopentano [b] furan-5H-yl - (+) - trans-chrysanthemum, that 3,3 aa, 4,5,6,6a-Hexahydro-2-oxo-4a-bromomethyl-2H-cyclopentano [b] furan-5 H -yl (+) - trans-chrysanthemate is reduced. Process variant (a) of claims 1 or 2-5. A process according to any one of claims 1 to 3 for the preparation of 3,3aaa, 4,5,6,6a-hexahydro-2-hydroxy-4a-chloromethyl-2H-cyclopentano [b] furan-5 / J-yl- (+) - trans-chrysanthemate. 3aa, 4,5,6,6aa-Hexahydro-2-oxo-4a-chloromethyl-2H-cyclopentano [b] furan-5S-yl (+) - trans-chrysatemate. Process variant (a) according to Claim 1, or Processes 2-5. A process according to any one of claims 1 to 3 for the preparation of 3,3aaa, 4,5,6,6a-hexahydro-2-hydroxy-4a-phenylthiourethyl-2H-cyclopentano [b] furan-5'-yl (+) - trans isantem, that 3.3aa, 4,5,6,6aa-Hexahydro-2-oxo-4a-phenylthiomethyl-2H-eiclopentano [b] furan-5'-yl- (+) - trans trans isantemate. Process variant (a) according to claim 1 or claims 2-5. A method according to any one of claims 1 to 6 3,3aa4,5,6,6aa-hexahydro-2-hydroxy-4a-kiórmetil-2H-cyclopentano [b] furan-5 / S-yl- [3- (2,2-dichlorovinyl) -2,2-dimethyl -cyclopropane- (1R, trans) -carboxylate], characterized in that 3.3aa, 4,5,6,6ax-hexahydro-2-oxo-4a-chloromethyl - 2H-Cyclopentano [b] furan-5β-yl - [3- (2,2-dichloro-vinyl) -2,2-dimethyl-cyclopropane - (R, t) -is] -carboxylate J is reduced. Process variant (a) according to claim 1 or claims 2-5. The process according to any one of claims 1 to 3, 3,3aa, 4,5,6,6aa-hexahydro-2-hydroxy-4a-bromomethyl-2H-cyclopentano [b] furan-5? - il - [3 - (2,2-dibromo-vinyl) -2,2-dimethyl-cyclopropane (1R, cis) -carboxylate], characterized in that 3,3aa, 4,5,6,6aa-hexahydro-2-oxo-4a - bromomethyl-2H-cyclopentano [b] furan-$ β-yl [3- (2,2-dibromo-vinyl) -2,2-dimethyl-cyclopropane - (R, cis) carboxylate]. 13. Process variant (a) of claims 1 or 2-5. The process according to any one of claims 1 to 3, 3, 3a, 4,5,6,6a-hexahydro-2-hydroxy-4a-phenylthiomethyl-2H-cyclopentanofibrofuran-5β-yl [3 (2,2-dibromo-vinyl) -2,2-dimethyl-cyclopropane ( R, cis) carboxylate], characterized in that 3,3aa, 4,5,6,6aa-hexahydro-2-oxo-4a-phenylthiomethyl-2H-cyclopentano [b] furan-5β-yl [3 - (2) , 2 - dibromovinyl) - 2,2 - dimethylcyclopropane (R, cis) carboxylate]. Process variant (b) according to claim 1 or claims 5-7. A process according to any one of claims 1 to 4 for the preparation of 3,3a, 4,5,6,6ax-hexahydro-2-hydroxy-4-bromomethyl-2H-cyclopentanol [b] furan-5β-yl (+) -transcitrate, characterized in that 3, 3aa, 4,5,6,6aa-hexahydro-2-methoxy - 4a-Bromomethyl-5 / J -hydroxy-2H-cyclopentano [b] furan was acylated with (+) - trans-chrysanthemic acid chloride to give 3,3aaa, 4,5,6,6a-hexahydro-2-methoxy-4a- bromomethyl-2H-cyclopentano [b] furan-5-yl- (+) - trans-chrysanthemate is hydrolyzed. 2 pieces of figure