HU180635B - Process for producing 3-substituted-2-cyclopentanoe derivatives - Google Patents

Abstract

3-Substituted-2-cyclopentenone derivatives of the general formula (I> <IMAGE> wherein R<1> and R<2> represent independently from each other a hydrogen atom or a straight-chained or branched C1-4 alkyl group, R<3> stands for a hydrogen atom or a C1-4 alkoxy group, Y represents hydrogen, or R<3> and Y together represent an oxygen atom or a double bond, are prepared by a) reacting a 2,5-dodecanedione derivative of the general formula (II), <IMAGE> with an alkali or alkaline-earth hydride or a lithium-(di-C1-6 alkyl amide) in an aprotic solvent, and reacting further the compound of the general formula (III) thus obtained, <IMAGE> with an acid; or b) reacting a compound of the general formula (III) with a base. The compound of the general formula (I) are - with the exception of one derivative - new and they serve as intermediates for the preparation of derivatives possessing valuable insect control activity.

Description

dr. Jenő Fekete chemical engineer 5% Budapest

A process for the preparation of 3-substituted-2-cyclopentenones

The present invention relates to a process for the preparation of formula (I). For the preparation of 3-substituted-2-cyclopentenones.

In the formula (I):

R ¹ and R ² each independently represent a straight or branched C 1 -C 4 alkyl group or hydrogen atom;

- R ³ represents a hydrogen atom or an alkoxy group;

- Y represents a hydrogen atom, respectively

R ³ and Y together represent an oxygen atom or a double bond.

Compounds of formula (I) are intermediates of valuable compounds of formula (IV) that possess insect growth inhibitory activity. (In the general formula (IV), R ^1, R ^2, R ³ and Y are as defined above, R is a linear or branched alkyl group.)

A derivative of the compounds of the present invention (wherein R ¹ , R ² , R ³ and Y are alkylene-alkyl) is known. The other compounds are new. The process according to the invention also represents a new production method for known chemical ethylene.

The only known compound of formula (I) has been used by Henrick, CA, et al., In the preparation of a compound of formula (IV) wherein R ¹ , R ² , R ³ and Y are each hydrogen, R ^{4 is} ethyl. (Bioorganic Chemistry 7, 235 (1978)). The compound thus obtained has been found to have a significant insect growth inhibitory effect. Yellow fever mosquito (Aedes aegypti) was found to be three times more effective than hydropren, three times more frequently than wax moth (Gallena mellonella), tenfew moth (Tenebrio molitor) and owl moth (Heliotis virescens).

Two processes have been developed for the preparation of the intermediate eiclopentonone (Bioorganic Chemistry 7, 235 (1978)):

In one of their processes, starting from 2,6-dimethyl-1-heptene, which was treated with diborane, the corresponding trialkylborane was obtained. The borane was reacted with bromine followed by sodium methoxide to give 1-bromo-2,6-dinethyl heptane. Reaction of the Grignard reagent with magnesium in an ethereal solution of the bromine compound with 3-ethoxy-2-cyclopentanone from diazomethane in 1,3-cyclopentanediol followed by removal of water from the resulting addition product with a low yield (13%) ¹ = R ² = R ³ = Y = H) eiclopentenone. The process is not economical due to expensive starting materials and reactants (diborane, diazomethane) and low production. Furthermore, the process is not suitable for the preparation of derivatives containing an alkoxy group (R ³ = O-alkyl in formula I) because of the known acid sensitivity of compounds containing such group.

In an improved version of the process, CA Henrick et al., First made hydroboration of 2,6-dimethyl-1-heptane to 1-hydroxy-2,6-dimethylheptane which was converted to 1-chloro-2,6-dimethylheptane with thionyl chloride. . The chlorine compound was converted to the corresponding alkyl lithium compound with metal lithium, which was reacted with 2-cyclopentenone formed from the cyclopentanone by bromination and subsequent elimination of hydrogen bromide. The resulting l-hydroxy-l- (2,6-dimethylheptyl) -2-cyclopentene with an ethereal solution of chromic acid [chromium (VI) oxide and sulfuric acid] were oxidized to the Formula (I) ^(R1 = ^R2 = ^R3 = Y = H) cyclopentenone. Although the process was feasible with higher yields, the disadvantage of the expensive starting materials used was that, for the synthesis of alkoxy-containing derivatives [R ³ = Oalkyl] in Formula I, due to the strongly acidic reagents used in the two reaction steps, suitable.

In the course of our research, we aimed to produce the known insect growth inhibitory compounds [R ¹ = R ² = R ^s = Y - HR = Et] in the general formula IV and also the novel compounds of the general formula IV having insect growth inhibiting properties. , The development of a simple, economical and easy to prepare process for the preparation of compounds of formula (I). It has been found that the known [R ¹ = R ² = R ³ = Y = H] in the formula (I) and the new 3-substituted-2-cyclopentenones of the formula (I) are simpler than the known process in less reaction steps. can be prepared from the novel 2,5-dodecanedione derivatives of formula II (wherein R ¹ , R ² , R ³ and Y are as defined above) by:

a) The 2,5-dodecanedione derivative of formula II is reacted with an alkali metal or alkaline earth metal hydride or lithium [di (C1-6-alkyl) amide] in an aprotic solvent, preferably an ether type solvent, followed by reacting the resulting compound of formula (III) with or without isolation, R ¹ , R ² , R ³ and Y as defined above; obsession

b) The compound of formula III (R ¹ , R ² R ³ and Y are as defined above) is reacted with a base, conveniently in a solvent, and if desired, the resulting compound of formula I is isolated from the reaction mixture.

Preferred metal hydrides are alkali metal hydrides such as sodium or potassium hydride. As lithium (di (C 1-6 alkyl) amide), lithium (diethylamide) and lithium (diisopropylamide) are preferred.

When proceeding in accordance with variant (a) of the process of the invention, preferred ethereal solvents (e.g., diethyl ether, dioxane, tetrahydrofuran, etc.) are used as the aprotic solvent.

If the intermediate of formula (III) prepared according to process variant (a) of the present invention is not isolated, it is converted to the target compound of formula (I) without any further action on the catalytic amount of base present in the reaction mixture.

When the process of variant b) of the present invention is carried out, the compound of formula III is conveniently dissolved in an organic solvent or water with a base, preferably an alkali metal or alkaline earth metal hydroxide or hydride (e.g., sodium hydroxide, 5% sodium hydroxide). etc.).

When an alkali metal or alkaline earth metal hydride of the process of the invention is used, the reaction is carried out at a temperature (-20) to -80 ° C, preferably 0 to 30 ° C.

When using lithium (di-C ₁ -C ₆ alkyl amide), _the reaction is carried out at a lower temperature, preferably from 0 ° C to -80 ° C, preferably from -30 ^° C to -70 ^° C. ALARM metal hydride such as lithium (di-C ₁ _ ₆ alkyl amide) of 15 was used and the reaction - in order to control side reactions vitSzaszorítása · - preferably carried out in atmosphere of inert gas.

A. Compounds of formula (II), which are the starting materials for variant (a) of the process of the invention, can be prepared according to our research by preparing commercially available or known citronella derivatives of formula (V) - R ¹ , R ² , R ³ and y is reacted with the methyl 25 vinyl ketone of formula (VI) above in the presence of a catalytic amount of one of the thiazolium salts of formula (VII):

- R ⁶ represents a linear or branched C1-5 alkyl, 2-hydroxyethyl group or a benzyl group 30;

R ^{e is} hydrogen or C 1-3 alkyl;

- R ⁷ represents a linear or branched C1-4 alkyl or 2-hydroxyalkyl group etil35;

- X ^- is a halide.

The reaction is carried out in the absence of a solvent or in an organic solvent, preferably dry dioxane, at a temperature not too high, preferably between 65 and 80-40 ° C. In the reaction, at least an equivalent amount of the base, preferably trialkylamines, is used. The product is recovered by extraction with or without direct vacuum distillation of the reaction mixture.

The procedures are illustrated by the following examples, without limiting our claims to these:

In each case, the analysis data is given in% by weight. Mass spectral data are indicated as Ms. 50. The composition of the chromatographic run-up mixture is given by volume.

Example 1:

7, ll-dimethyl-ll-methoxy-2,5-dodekándion Preparation of [(II): ^R1 = ^R2 = Y = H; R ³ = OCH ₃ ]

37.3 g (0.2 mole) of 7-methoxy-6,7-dihydro-citronellal, where R ¹ = R ² = Y = H; R ³ = 0CH ³ ] 21 g (0.3 mol) of distilled methyl vinyl ketone (VI) and 60 5 g (0.02 mol) of 3-benzyl-5- (2-hydroxyethyl) -4-methyl- thiazolyl chloride [R ⁵ = benzyl, R ^e = CH 3; R ⁷ = CH ₂ -CH ₂ -OH; X = Cl] was heated to 70 ° C and then 3.64 g (5 mL, 0.036 mol) of dry triethylamine was added and stirred under argon at 65-75 ° C for 16 hours. The reaction mixture was cooled, poured into a mixture of 150 mL of 5% sulfuric acid and 15 g of ice, and extracted twice with 300 mL of dichloromethane. The extract was washed with water (20 mL), 5% sulfuric acid (20 mL), again water (20 mL), dried over magnesium sulfate, the solvent was distilled off and the residue was distilled at 0.2 torr.

Yield: 23 g (44.9%) MP: 110-114 ° C / 0.2 mm. Analysis: C ₁₅ H ₂₈ O ₃ (256.37) 10

Calculated: C 70.26% H 11.15% Found C 69.98% H 11.00%.

IR (NaCl): 1715, 1460, 1400, 1380, 1360, 1150, 1070 cm ^-1 .

1 H-NMR (CCl ₄ ): 0.9 (3H, d, J = 6Hz, CH ₃ ), 1.1 15 6H, s, 2CH ₃ ), 1.3 (6H, mc, 3CH ₂ ), 2 1 (3H, s, • CH _3), 2.58 (4H, s, _2-a), 3.08 (3H, s, 0CH _3).

Ms: M ⁺ 256 (2%); m / e 241 (10), 226 (15), 225 (20), 210 (10), 186 (25), 131 (8), 99 (90), 73 (100), 43 (95). 20

Example 2 3- (2,6-Dimethyl-6-methoxy-heptyl (-3-hydroxycyclopentanone [(III): R ¹ = R ² = Y = H; R ³ = OCH ³ )] and 3- (2, 6-dimethyl-6-methoxyheptyl) -2-cyclopentenone 25 [(I): R 1 = R ³ = Y = H; R ³ = OCH ³ ].

To a suspension of 0.5 g (0.0176 mol) of sodium hydride (80% suspension) in 20 ml of dry ether under stirring under argon is added 2.56 g (0.01 mol) of 7,11-dimethyl-11 -methoxy-2,5-dodecanedione 30 [(II): R 1 = R ² = Y = H; A solution of R ³ = OCH ₃ ] in dry ether (10 mL) was added dropwise over half an hour, and the mixture was stirred at room temperature for six hours. The reaction mixture was poured into ice water, the organic phase was separated, the aqueous phase was extracted with ether (20 mL), the combined organic phases were washed with water, dried over magnesium sulfate and the solvent removed by evaporation to give an oily residue. 0,2). 4Q

3- (2,6-Dimethyl-6-methoxy-heptyl) -3-hydroxy-cyclopentanone:

Yield: 0.80 g (31.3%)

R f = 0.25 (benzene-methanol 10: 1).

IR (NaCl): 3410.1720, 1460.1380, 1350, 1230, 1140, 1060 45 enr ^first

1 H-NMR (CDCl ₃ ): 0.9 (3H, d, J = 6Hz, CH ₃ ), 1.05 (6H, s, 2CH ₃ ), 1.3 (6H, mc, 3CH _a ), 2.1 (4H, mc, 2 CH _2), 2.55 (2H, mc, _CH2), 3.05 (3H, s, _OCH3), 3.55 (1H, mc, deuterium replaceable stem 53 eh , OH).

Ms: M ⁺ 256 (1%), m / e 238 (2), 207 (37), 206 (2), 188 (11), 183 (3), 150 (2), 135 (3), 123 ( 4), 109 (5), 108 (4), 96 (3), 93 (5), 91 (7), 85 (8), 81 (5), 73 (100). ₅₅

3- (2,6-Dimethyl-6-methoxy-heptyl) -2-cyclopentenone: Yield: 0.45 g (18.9%) Rf = 0.47 (10: 1 benzene-methanol).

Analysis: C ₁₅ H _2e O ₂ (238.36) Calculated: C 75.58 H 11.00 60

Found: C, 75.07; H, 10.72%.

IR (NaCl): 1705.1615, 1460, 1430, 1400, 1380, 1360, 1270, 1240, 1160, 1070 cm ^-1 .

1 H-NMR (CCl ₄ ): 0.9 (3H, d, J = 6Hz, CH ₃ ), 1.05 (6H, s, 2CH ₃ ), 1.3 (6H, mc, 3CH ₂ ), 2.3 (6H, m c 65 + m, _3-CH2), 3.03 (3H, s, _OCH3), 5.75 (1H, m, CH).

Ms: M ⁺ 238 (1%), M / e 223 (1), 207 (3), 165 (4), 151 (2), 135 (2), 124 (3), 123 (7), 109 ( 3), 108 (2), 96 (8), 95 (7), 93 (4), 85 (11), 81 (8), 73 (100).

2- (1,5-Dimethyl-5-methoxy-hexyl) -3-methyl-2-cyclopentenone formed as a by-product in the reaction: Yield: 0.24 g (10.08%), Rf = -0.64 (benzene). -methanol 10: 1).

Analysis: C ₁₅ H ₂₆ O ₂ (238.36) Found: C 75.58 H 11.0 Found: C 75.42 H 11.21%.

IR (NaCl): 1690, 1630, 1460, 1380, 1360, 1200, 1070 cm ^-1 .

1 H-XMR (CDCl ₃ ): 1.05 (6H, s, 2CH ₃ ), 1.1-1.7 (10H, m, 3CH ₂ , CH, CH ₃ ), 2 (3H, s, CH ₃ ) 2.4 (4H, m, 2CH _2), 3.02 (3H, s, _OCH3).

Ms: M ⁺ 238 (2%), m / e 223 (1), 206 (5), 151 (10), 150 (7), 135 (7), 124 (6), 123 (6), 109 ( 3), 95 (4), 93 (4), 91 (3), 85 (2), 81 (6), 73 (100).

EXAMPLE 3 3- (2,6-Dimethyl-6-methoxy-dimethylheptyl) -2-cyclopentenone előállí'ása [(I): R ¹ = R ² = Y = H; R ³ = OCH ³ ] To a suspension of 2 g (0.16 mol) of sodium hydride (80% oily suspension in 30 ml of dry ether) under nitrogen, 5.12 g (0.02 mol) of 7,11 A solution of dimethyl-11-methoxy-2,5-dodecanedione [(II: R ¹ = R ² = Y = H; R ³ = 0CH ³ ) in dry ether was added dropwise over half an hour, and the resulting suspension was stirred at room temperature for 12 hours. The reaction mixture was poured into a mixture of 5% hydrochloric acid (20 ml) and ice (30 g), the organic phase was separated, the aqueous phase was extracted with ether (30 ml), the combined organic extracts washed with water, dried over magnesium sulfate and evaporated.

The residue was dissolved in a mixture of 25 ml of ethanol and 50 ml of 0.5 N sodium hydroxide and the solution was refluxed for 2 hours. The reaction mixture was cooled to room temperature, extracted twice with a total of Ϊ00 mL of ether, the ether extract was washed with 20 mL of brine, dried over magnesium sulfate, the solvent was distilled off and the residual oil was purified by column chromatography. (Silica gel 60; benzene methanol 10: 0.2). Yield: 2.16 g (45.38%), m.p.

Example 4 Preparation of 3- (2,6-Dimethyl-6-methoxy-heptyl) -2-cyclopentenone [(I): R ¹ = R ³ = Y = H; R ³ = OCH ₃ ]

To a solution of 1.3 g (0.013 mol) of dry diisopropylamine and 10 ml of hexamethylphosphoric triamide in 30 ml of tetradhydrofuran at -65 ° C under argon was added 0.9 g (0.014 mol) of butyl lithium. of butyl lithium in hexane, and the mixture is stirred for half an hour at -30 ° C. The reaction mixture was cooled to -65 ° C and 2.56 g (0.01 mol) of 7,11-methoxy-2,5-dodecanedione [(II): R ¹ = R ³ = Y = H were added dropwise over two hours. ; R ³ = OCH _S ] in 30 ml of dry tetrahydrofuran. The mixture was heated for one hour to -65

Stir at -3180635 ° C and then for 3 hours at room temperature.

The reaction mixture was poured into water and extracted twice with 100 ml of ether. The ether extract was washed with water, brine, dried over magnesium sulfate, the solvent was distilled off and the residue was purified by column chromatography. (Kieselgel 60; benzene-methanol 10: 0.2).

Yield: 1.0 g (42%), m.p.

EXAMPLE 5 3- (2,6-Dimethyl-6-methoxy-dimethylheptyl) -2-cyclopentenone [(I): R ¹ = R ² = Y = H; R ³ = 0CH ₃ ]

1.2 g (0.0047 mole) of 3- (2,6-dimethyl-6-methoxy-heptyl) -3-hydroxy-cyclopentenone [(KIC): R ¹ = R ² = Y = H; R ³ = OCH ₃ ] is dissolved in a mixture of 25 ml of ethyl alcohol and 25 ml of 0.5 N sodium hydroxide and the solution is refluxed for 2 hours. The reaction mixture was cooled to room temperature and extracted twice with 100 ml of ether each time. The combined ethereal extracts were washed with water, saturated brine, dried over magnesium sulfate, and after evaporation of the solvent, the residue was purified by column chromatography (Kieselgel 40; benzene-methanol 10: 0.05). Yield: 0.7 g (63%), m.p.

Example 6

Preparation of 7,1-Dimethyl-2,5-dodecanedione [(II): R ¹ = R ² = R ³ = Y = H]

19.5 g (0.125 mol) of dihydro-citronellal [(V): R ¹ = R ² = R ³ = Y = H], 14 g (0.2 mol; 16 ml) of freshly distilled methyl vinyl ketone ( VI) and 2.0 g (0.01 mol) of 3-ethyl-5- (2-hydroxyethyl) -4-methylthiazolium chloride [(VII): R ⁵ = Et, R ⁶ = CH 3; R ⁷ = CH ₂ -CH ₂ • -OH; 1.82 g (0.018 mol) of a solution of X ^- = Cl ^- ] in 50 ml of dry dioxane; 2.5 ml] of triethyl aniline are added and the mixture is heated in an oil bath at 80 ° C for 24 hours. After cooling, the precipitate formed is filtered off, the solvent is distilled off and the residue is distilled at 1 torr.

Yield: 11 g (48.7%).

Mp: 103-105 ° C / 0.2 mm; 128-130 ° C / 1 mm. N "= 1.442

Analysis: C ₁₄ H ₂₆ O ₂ (226.35) Calculated: C 74.28 H 11.58 Found: C 73.96 H 11.32%. IR (NaCl): 1715, 1460, 1380, 1360, 1140, 1080 cm ^-1 . 1 H-NMR (CCl ₄ ): 0.9 (9H, d, J = 6Hz, 3CH ₃ ), 1.2 (6H, mc, 3CH ₂ ), 2.1 (3H, s, CH ₃ ), 2 2 (2H, m, _CH), 2.58 (4H, s, 2CH _2).

Ms: M ⁺ 226 (5%); m / e 114 (100), 113 (29), 99 (46), 71 (90), 56 (36).

Example 7 3- (2,6-Dimethylheptyl) -3-hydroxycyclopentanone [(III): R ¹ = R ² = R ³ = Y = H] and 3- (2,6-Dimethylheptyl) Preparation of -2-cyclopentenone [(I): R ¹ = R ² = R ³ = Y = = H]

To a suspension of 1.0 g (0.033 mol) of sodium hydride (80% w / w oily suspension) in 40 mL of dry ether was added dropwise 3.0 g (0.013 mol) of 7,11-dimethyl-2.5 under argon. solution of dodecanedione [(II): R ¹ = R ² = R ³ = Y = H] in dry ether for half an hour, and the mixture was stirred at room temperature for 10 hours. The reaction mixture was poured into 20 ml of 5% hydrochloric acid and 40 g of ice, extracted twice with 100 ml of ether each time, and the combined extracts were washed with water, brine, dried over magnesium sulfate and chromatographed after distilling off the solvent. (Kieselgel G; benzene-methanol 10: 0.05).

3- (2> 3-dimethyl-heptyl) -3-hydroxy-cyclopentenone; Yield: 0.72 g (24.5%)

Rf 0.28 (benzene-methanol 10: 0.1).

IR (NaCl): 3410, 1720, 1460, 1380, 1360, 1220 cm ^-1 . 1 H-NMR (CDCl ₃ ): 80.9 (9H, d and d, J = 6Hz, 15 3 CH ₃ ), 1.28 (6H, mc, 3CH ₂ ), 2.3 (8H, mc,

4CH ₂ ), 3.35 (1H, m, exchangeable deuterium, OH).

3- (2,6-Dimethylheptyl) -2-cyclopentenone: Yield: 1.1 g (40.62%)

R f = 0.62 (benzene-methanol 10: 0.2). Analysis: C ₁₄ H ₂₄ O (208.33) Calculated: C 80.70 H 11.61 Found: C 80.49 H 11.42

IR (NaCl): 1705, 1615, 1460, 1380, 1360, 1250, 1130, 25 1090 cm -1.

H-NMR (CDC1 _3): 80.9 (9H, d and d, J = 6 Hz, _3-a), 1.3 (6H, m c, _3-CH2), 2.4 (6H, m c, _3-CH2 ), 5.95 (1H, m, = CH).

2- (1,530-Dinethylhexyl) -3-methyl-2-cyclopentenone formed as a by-product in the reaction: Yield: 0.29 g (10.74%), Rf = 0.83 (benzene-methanol 10: 0, 2). Analysis for: C ₄ H ₂₄ O (208.33) Calculated: C 80.70 H 11.61

Tahit: C, 80.64; H, 11.47%.

IR (NaCl): 1690, 1630, 1460, 1400, 1380, 1360, 1320, 1290, 1260 ^cm-first

1 H-NMR (CDCl ₃ ): δ 0.9 (6H, d, J = 6Hz, 2CH ₃ ), 1- 1.8 (10b, m, 3CH ₂ , CH, CH ₃ ), 2 (3H, s, CH 2), 40 2.35 (5Ή, mc, 2CH ₂ , CH).

Example 8

3- (2,6-Dnnetil-dimethylheptyl) -2-cyclopentenone [(I), ^R1 = ^R2 = ^R3 = Y = H]

To a solution of 1.3 g (0.013 mol) of dry diisopropylamine and 5 ml of hexamethylphosphoric triamide in 20 ml of dry tetrahydrofuran at -65 ° C under argon is added 0.9 g (0.014 mol) of butyl of lithium in 15% w / w butyl lithium in hexane and stirred for 20 minutes at -30 ° C. The reaction mixture was cooled to -65 ° C and 2.26 g (0.01 mol) of 7,11-dimethyl-2,5-dodecanedione [(II): R ¹ = = II ² = R ³ = Y = H were added dropwise. ] In dry tetrahydrofuran (20 mL) over two hours. The mixture was stirred at room temperature for -65 ^c C, then 6 hours an additional hour.

The reaction mixture was poured into water and extracted twice with 100 ml of ether. The combined ether extracts were washed with water, saturated brine, dried over magnesium sulfate (60), the solvent was distilled off and the residue was purified by column chromatography (silica gel 60; benzene methanol 10: 0.05).

Yield: 0.91 g (43.75%), m.p.

Example 9

7.11- Preparation of dimethyl-10-dodecene-2,5-dione [(II): R ³ = R ² = H; R ³ + Y = electron pair]

15.4 g (0.1 mole) of citronellal [(V): R ¹ = R ² = H; R ³ + Y = electron pair], 14 g (0.2 mol; 16 ml) of freshly distilled methyl vinyl ketone (VI) and 3.1 g (0.01 mol) of 3-ethoxyethyl-5- (2 -hydroxyethyl) -4-ethylthiazolium bromide [(VII): IU = EtO-CH _a -CH _a -; R '= CH _S ; R '= CH ₂ -CH ₂ -OH; To a solution of X = Br] in 40 mL of dry dioxane was added dry triethylamine (1.82 g, 0.018 mol) and the mixture was stirred under argon for 24 hours at 80 ° C. After cooling, the precipitate formed is filtered off, the solvent is distilled off and the residue is distilled off in vacuo.

Yield: 10.5 g (46.8%), m.p. 105-107 ° C / 0.2 mm λ = 1.470.

IR (NaCl): 1715, 1460, 1380, 1360 cm -1.

NMRíCCl). 80.9 (3H, d, J = 6Hz, _CH3), 1.2 (12H, mc, and _the 3 CH 2 CH _3), 2.1 (3H, s, CH ₃₎ 2, 58 (4H, s, 2CH _2), 5.1 (1H, m, CH).

Ms: M ⁺ 224 (10%), m / e 206 (19), 166 (66), 153 (13), 141 (42), 114 (16), 110 (49), 99 (100), 71 (44,) 69 (71), 55 (39), 43 (90), 41 (71).

EXAMPLE 10 3- (2,6-dimethyl-5-heptenyl) -2-cyclopentenone [(I): R ¹ = R ² = H; R ³ + Y = electron pair]

To a solution of 2.6 g (0.026 mol) of dry diisopropylamine in 10 ml of hexamethylphosphoric triamide and 40 ml of dry tetrahydrofuran was added 1.8 g (0.028 mol) of butyl under nitrogen with stirring at -65 ° C under nitrogen. 15% w / w solution of butyl lithium in hexane and stir for half an hour at -30 ° C. The reaction mixture was cooled to below -60 ° C and 4.5 g (0.02 mol) of 7,11-dimethyl-10-dodecene-2,5-dione [(II): R ¹ = R ² = H; R ³ + Y = electron pair] in 30 mL of dry tetrahydrofuran over two hours. The mixture was stirred at -55 ° C for one hour and then at room temperature for 8 hours.

The reaction mixture was poured into water, extracted twice with 100 ml of ether each time, the combined extracts were washed with water, brine, dried over magnesium sulfate, evaporated and the residue was purified by column chromatography (Kieselgel 60; benzene-methanol 10: 0.05). : 1.4 g (34%)

Rf = 0.7 (benzene-methanol 10: 0.3).

IR (NaCl): 1705, 1615, 1460, 1380, 1250, 1150, 1090 cm ^-1 .

Ή NMR (CCl _o): 09 (3H, d, J = 6Hz, _CH3), 1.2 (12H, c, and _S 3 CH 2 CH _3), 2.3 (6H, m c, _3-CH2) , 5.1 (1H, m, .dbd.CH).

Example 11

7.11- Preparation of Dinethyl-11-ethoxy-2,5-dodecanedione [(II): R 1 = R ² = Y = H; R _s = OCH ₂ CH _S ] g (0.1 mol) 7 ethoxy-6,7-dihydrocytonellal [(V): R ¹ = R ² = Y = H; R ⁸ = OCH 2 CH 3], 10.5 g (0.15 mol) of distilled methyl vinyl ketone (VI) and 2.5 g (0.01 mol) of 3-benzyl-5- (2-hydroxyethyl) - 4-methyl-thiazolium chloride [(VII): R ⁵ - benzyl cs .; R ⁶ = CH 3; R '= = CH ₂ -CH ₂ -OH; X = Cl] was heated to 70 ° C and then 1.8 g (2.5 mL, 0.018 mol) of dry triethylamine was added under nitrogen under a 75 ° C oil bath for 16 hours. The reaction mixture was cooled to room temperature, poured into a mixture of 100 ml of 2.5% sulfuric acid and 25 g of ice, and extracted twice with 150 ml of dichloromethane each. The extract was washed with water, 5 wt% sulfuric acid, water again, dried over magnesium sulfate, the solvent was distilled off and the oily residue was evaporated in vacuo.

Yield: 11.6 g (42.96%) Fp = 112-114 ° C / 0.2 mm. Analysis: C ₁₆ H ₃₀ O ₃ (270.40) Calculated: C 71.07 H 11.18 Found: C 70.86 H 10.80%.

IR (NACI): 1715, 1460, 1380, 1360, 1150, 1070 cm ^-1 . HRNMR 1 ClCl): 80.9 (3H, d, J = 6Hz, CH ₃ ), 1.3 (15H, mc, 3CH _a , 3CH ₃ ), 2.1 (3H, s, CH _S ), 2, 55 (4H, s, _2-a, 3.6 (2H, q, J = 6Hz, _OCH2).

Example 12 Preparation of 3'-2,6-Dimethyl-6-ethoxy-heptyl) -2-cyclopentenone [I]: R 1 = R ² = Y = H; R ³ = 0CH _a -CH _a ]

To a solution of 2.6 g (0.026 mol) of dry diisopropylamine and 10 ml of 1 examethylphosphoric triamide in 50 ml of dry tetrahydrofuran, cooled to -65 ° C under nitrogen, is added 1.8 (0.028 mol) of butyl lithium containing 15% (w / w) butyl lithium in hexane and stirred for half an hour at -30 ° C. The reaction mixture is cooled to -65 ° C and 5.4 g (0.02 mol) of 7,11-dimethyl-11-ethoxy-2,5-dodecanedione [(II): R ¹ = R ² = Y are added dropwise. = H; R ³ = = OCH _in CH ₃ ] in 20 mL dry tetrahydrofuran for two hours. The mixture was stirred at -65 ° C for one hour and then at room temperature for 8 hours.

The reaction mixture was poured into water, extracted twice with 100 ml of ether each time, and the combined extracts were washed with water, brine, dried over magnesium sulfate, evaporated and the residue was purified by column chromatography (Kieselgel 60; benzene methanol 10: 0.1). Yield: 1.9 g (37.7%).

Rf 0.53 (benzene-methanol 10: 1). Analysis: C ₁₆ H _{as the} O (252.38) Calculated: C 76.14 H 11.18 Found: C, 75.91; H, 10.89%.

IR (NaCl): 1705.1615.1460, 1380, 1270, 1240, 1155, 1065 cm ^-1 .

1 H-NMR (CDCl ₄ ): 80.9 (3H, d, J = 6Hz, CH ₃ ), 1.05 (6H, s, 2CH ₃ ), 1.3 (9H, mc, 3CH _a , CH _3). )

2.3 (6H, mc, m, 3CH _a ), 3.6 (2H, q, J = 6 Hz, OCH _a ), 5.78 (1H, m, = CH).

Claims (6)

A process for the preparation of the 3-substituted-2-cyclopentenones of formula (I): wherein: R ¹ and R ² each independently is hydrogen or a linear or branched C 1 -C 4 alkyl group; -511 R ^{3 represents a} hydrogen atom, an alkoxy group or an oxygen atom; Y is hydrogen; or R ³ and Y may be taken together to represent an oxygen atom or a double bond, characterized in that a) The 2,5-dodecanedione derivative of formula II is reacted with an alkali metal or alkaline earth metal hydride or lithium [di (C 1-6 alkyl) amide in an aprotic solvent, preferably ether, and the resulting The compound of formula III, wherein R ¹ , R ² , R ³ and Y are as defined above, is further reacted with or without isolation, or b) (III), a compound of formula - R ^x, R ^2, R ³ and Y are as defined above - is reacted with a base in a solvent, and if desired the resulting compound of formula (I) is isolated from the reaction mixture. Process according to claim 1, variant a), characterized in that the reaction is carried out using an alkali metal hydride, preferably sodium hydride. 3. The method of claim 1, variant a), 5 wherein 11 je emezve to lithium (di-C ₁ _ ₆ alkyl amide) as lithium (diethylamide) was used and lithium (lithium diisopropylamide) respectively. The method of implementing the method of claim 1, variant b), Characterized in that the base is an alkali metal or alkaline earth metal hydroxide, preferably sodium hydroxide. A method of carrying out the method of claim 1, variant a), Characterized in that the reaction with a metal hydride is carried out in an aprotic solvent, preferably ether. 6. A method according to claim 1, variant a), wherein The reaction was carried out with lithium di-C 1 -alkylamide in tetrahydrofuran-hexamethylphosphoric triamide.