JPS6059236B2 - γ-pyrone derivatives, their production methods, and agricultural drugs comprising these compounds - Google Patents

Description

Detailed Description of the Invention The present invention is based on the general formula (wherein R1 and R2 represent a lower alkyl group, R represents a linear or branched saturated or unsaturated hydrocarbon group, and The present invention relates to a novel compound represented by (the hydrocarbon group may be substituted with a phenyl group), a method for producing the same, and an agricultural drug.

In living organisms, electron transport systems are essential for the progression of biochemical reactions such as respiration and photosynthesis.

The insecticidal components Piericidin A and B produced by StreptOmycesm Obaraensis are the coenzyme Ubiqui in the mitochondrial electron transport chain.
It is known to strongly and competitively inhibit the action site of nOrle. The present inventors believe that such a Pierici
The present invention was completed by conducting research to find the essential structure for the expression of the activity of dins. (In the formula, Rl, R2 and R
has the same meaning as above) In other words, there is almost no precedent for the synthesis of asymmetric tetrasubstituted γ-pyrones, which is the object of the present invention, but as a result of examining various synthesis methods, completed the first synthetic method for γ-pyrone derivatives.

The γ-pyrone derivative synthesized by the above method was a lipophilic oily substance.

The spectra of each instrumental analysis showed typical patterns of γ-pyrone derivatives. The effect of the synthesized γ-pyrone derivative on the photosynthetic system was examined by assaying its ability to inhibit the Bill reaction using chloroplasts extracted from spinach leaves.

The building reaction inhibiting activity of the γ-pyrone derivatives is listed in the table below. The results for γ-pyrone derivatives suggested that heterocyclic compounds having the same substitution mode as plastoquinone have the ability to inhibit the Bill reaction. Next, Examples will be given to further specifically explain the present invention, but the present invention is not limited to the following Examples.

Example 1 (In the formula, R has the same meaning as above) α-acetopropionate ethyl (1), 144y (1 mol) was mixed with ethylene glycol 68f (1.1 mol) and anhydrous benzene 400 ml, and The mixture was placed in a 1e round bottom flask connected to a starch trap.

Add 0.0% p-toluenesulfonic acid to this mixture as an acid catalyst.
4y (0.024 mol) was added, and the mixture was heated until 18 mt of water separated in the Dean-Stark trap, and the benzene was refluxed. After cooling the reaction solution to room temperature,
Wash with 150 ml of 10% caustic soda solution, then 1
Washing was repeated three times with 00 ml of water. The organic phase was dried with anhydrous sodium sulfate and purified by vacuum distillation. Target α
-The ketalized product (2) of ethyl acetopropionate is 74pC/3Tfr! Distilled with NHy, yield 170y
(yield 85%). A 200 ml four-necked flask was equipped with a stirrer, a dropping pouch, and a reflux condenser cooled with dry ice-acetone cryogen to keep the interior dry. Cool to -80'C, being careful to
50 ml of liquid ammonia was injected. Sodium amide was prepared from this ammonia and 1.15y (0.05 mol) of metallic sodium. This sodium amide was suspended in 50 ml of anhydrous ether, and about 1 drop of a solution of 2.85 V (0.025 mol) of isoamyl methyl ketone in 20 ml of anhydrous ether was added dropwise with vigorous stirring under room temperature conditions. After dropping, stirring was continued, and then 9.4% of the ketalized product (2) of ethyl α-acetopropionate was added.
A solution of f (0.05 mol) in 20 mt of anhydrous ether was added dropwise in one drop. Thereafter, stirring under heating and refluxing was continued for 3 hours, and finally the reaction solution was added to 100 ml of ice water and neutralized to pH 6-7 with 2N hydrochloric acid. The target product was extracted with ether, washed sequentially with saturated sodium carbonate solution and water, dried over anhydrous sodium sulfate, and then the ether was distilled off.The target product was present in the residue, but was subjected to the ring-closing reaction without purification. 3-methyl-2,
10 mL of concentrated sulfuric acid was gradually added to the mixture 4.2y containing 4-diketopentyl-isoamyl-ketone-2-ethylene ketal (3) as the main component with sufficient stirring under ice cooling.

After continuing cooling and stirring for 1 hour, 200 ml of ice water was added, and the mixture was further neutralized with sodium bicarbonate (pH 7-8) and extracted with ethyl acetate. After distilling off the ethyl acetate, the extract was
It was purified by silica gel column chromatography using an elution solvent system of hexane-ethyl acetate. Target 6-isoamyl-2,3-dimethyl-γ-pyrone (4
) in the elution section of hexane/ethyl acetate (7:3).
37 m9 (0.003 mol) was obtained. [Yield from ketalized product (2) of ethyl α-acetopropionate is 13%] Example 2 0.05 mol of sodium amide used in Example 1 was
3.55y (4). 025
About 1 mol of 20 ml of anhydrous ether solution was added dropwise with vigorous stirring.

After the completion of the dropping, 9.4 g (0.05 mol) of the ketalized product (2) of ethyl α-acetopropionate was mixed with 2
Approximately 1 drop of 0 ml of anhydrous ether solution was added. After that, heating under reflux and stirring was continued for 3 hours, and finally, the reaction solution was added to 100ml of ice water, and the pH was further adjusted with 2N diluted hydrochloric acid.
Neutralized to 6-7. The neutralized solution was extracted with ether, washed and dried according to a conventional method, and the ether was distilled off.
A crude product of 3-methyl-2,4-diketopentyl-hebutyl-ketone-2-ethylene ketal (3) was obtained.
To this crude product was gradually added 10 ml of concentrated sulfuric acid under ice-cooling with vigorous stirring. After cooling and stirring for 1 hour, 200ml of ice water was added, followed by pH addition with bicarbonate of soda.
It was neutralized to 7-8 and extracted with ethyl acetate. After distilling off the solvent, the extract was purified by silica gel column chromatography. 680 m9 of the target 6-heptynole-2,3-dimethyl-γ-pyrone was obtained in the elution section of hexane/ethyl acetate (7:3) (as the yield from the ketalized product (2) of ethyl α-acetopropionate). 12%
). Next, typical compounds obtained by the method of the present invention will be listed, but the present invention is not limited to the following exemplified compounds.

Claims (1)

[Claims] 1 General formula ▲ Numerical formula, chemical formula, table, etc. ▼ (In the formula, R_1 and R_2 represent a lower alkyl group, R
represents a linear or branched saturated or unsaturated aliphatic hydrocarbon group. 2 General formula ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ (In the formula, R_1 and R_2 represent lower alkyl groups, and R
_3 represents an alkyl group) is reacted with ethylene glycol to form the general formula ▲mathematical formula,
There are chemical formulas, tables, etc. ▼ (In the formula, R_1, R_2, and R_3 have the same meanings as above.) Obtain a ketal compound, and then combine this compound with the general formula ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ (In the formula R represents a linear or branched saturated or unsaturated aliphatic hydrocarbon group) A general formula ▲Mathematical formula, chemical formula, table A method for producing a γ-pyrone derivative represented by ▼ (wherein R_1, R_2 and R have the same meanings as above). 3 General formula ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ (In the formula, R_1 and R_2 represent lower alkyl groups, and R
represents a linear or branched saturated or unsaturated aliphatic hydrocarbon group) as an active ingredient.