JPS6126975B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a method for producing a 3-oxocyclopentene compound, and more particularly, to a method for producing a 3-oxocyclopentene compound, more specifically, a method for producing a 3-oxocyclopentene compound, and more specifically, [In the formula, R ₁ is an alkyl group with up to 6 carbon atoms, an alkenyl group with up to 6 carbon atoms that does not have an unsaturated bond at the bond end, an alkynyl group, or a general formula

[In the formula, R ₁ represents the same meaning as above, and X represents a chlorine atom, a bromine atom, or an iodine atom. ]

General formula () R ₁ MX () obtained by reacting Mg, Zn or Al metal to _the compound represented by
represents Mg, Zn or Al2/3 atoms. ] It can be obtained by reacting the compound represented by these with 5-methylfurfural. Hereinafter, the present invention will be specifically explained with reference to Examples. Example 1 Prepare 1 water and 25 g of 5-methyl-2-furyl-allyl-carbinol, add 1N NaOH and 1N
The pH was adjusted to 5.5 with aqueous HCl. This was heated to 100° C., refluxed, maintained at pH 5.0 to 5.5 with 1N NaOH and 1N HCl aqueous solution, and stirred under reflux for 12 hours. next
After cooling to 40℃ and neutralizing with 1N-NaOH water, add 300% salt.
g and extracted 5 times with 100 ml of toluene. Toluene was distilled off from the extract under reduced pressure at 60°C to obtain 23 g of oil. Next, this was distilled at 0.1 mmHg and 77℃.
21.3 g of 4-hydroxy-4-methyl-5-
Allyl-2-cyclopentenone was obtained. Yield 85.2
% NMR data ( _CCl4 , internal standard TMS, δppm,
60MHz) 7.32 (d, 1H, 3-H), 5.92 (d, 1H, 2-
H), 5.81 (complex m, 1H, _-CH2 - CH =
CH _a H _b ), 5.12 (m, 1H, -CH ₂ -CH=CH a _{H b} ), 4.93 (m, 1H, -CH ₂ -CH=CH _a H _b ), 4.12 (broad S, 1H, 4- OH ) 2.37(m, 3H, 5-H& -CH2 - _CH =
CH _a H _b ) 1.28 (S, 3H, 4- CH ₃ ) Example 2 Prepare 200 ml of water and 5 g of 5-methyl-2-furyl-propargyl-carbinol, and adjust the pH to 4 with 1N NaOH and 1N HCl aqueous solution. Prepared. this
Heat to 100℃ and reflux, add 1N NaOH and 1N
The mixture was stirred under reflux for 16 hours while maintaining the pH at 3.8 to 4.1 with an aqueous HCl solution. Next, after cooling to 40℃ and neutralizing with 1N NaOH water,
60 g of common salt was added and extracted 5 times with 20 ml of toluene.
Toluene was distilled off from the extract under reduced pressure at 60℃, and 4.0g
of oil was obtained. Next, use 60 g of silica gel to prepare ethyl acetate/n-hexane (1 volume vs. 2 volumes).
to obtain the desired 4-hydroxy-4-methyl-5-propargyl-2-cyclopentenone.
3.7g was obtained. Yield 74% NMR data (CDCl ₃ internal standard TMS, δppm,
90MHz) 7.30 (d, 1H, 3-H), 5.90 (d, 1H, 2-
H), 3.80 (broad s, 1H, 4- OH ) 1.98 (S, 1H, -C≡CH ) , 1.30 (s, 3H,
4- CH3 ) Example 3 40 ml of water and 0.5 g of 5-methyl-2-furyl-n-butyl _- carbinol were added, and 1N NaOH and
The pH was adjusted to 5 with 1N HCl aqueous solution. This at 100℃
The temperature was raised to reflux, the pH was maintained at 5 to 5.5 with 1N NaOH and 1N HCl aqueous solution, and the mixture was stirred under reflux for 30 hours. Next, after cooling to 40℃ and neutralizing with 1N NaOH water, salt
Add 12g and extract 5 times with 40ml of toluene. Toluene was distilled off from the extract under reduced pressure at 60°C to obtain 0.48 g of oil. This was developed using silica gel thin layer chromatography with ethyl acetate-n-hexane (1 volume to 2 volumes). The desired fraction was scraped off, eluted with ethyl acetate, filtered through silica gel, and concentrated to obtain 3.5 g of 4-hydroxy-4-methyl-5-n-butyl-2-cyclopentenone. Yield 70% NMR data ( _CCl4 internal standard TMS, δppm,
60MHz) 7.25 (d, 1H, 3-H), 5.85 (d, 1H, 2-
H), 3.63 (broad s, 1H, 4- OH ) 2.20 (m, 1H, 5-H) 1.25 (S, 3H, 4- CH ) Examples 4 to ₉ 0.5 g of the following furancarbinol compound The same operation as in Example 3 was performed using the following conditions under the following conditions to obtain each 3-oxocyclopentene compound.

【table】

[Table] * Contents Example ₁ of R1 of the compound represented by the above general formulas 〓 and 〓 10 Charge 750 ml of water, heat to 100°C, and reflux. Next, a solution prepared by dissolving 24 g of 5-methyl-2-furyl-allyl-carbinol and 1.5 g of MgCl ₂ .6H ₂ O in 160 ml of water was added dropwise over 2.5 hours and 3.5 hours, respectively. At that time, the pH of the reaction solution was controlled to be between 5.7 and 5.3 using a 10% monopotassium phosphoric acid aqueous solution and 1N aqueous sodium hydroxide. The pH stopped changing around 1.5 hours after the start of the reaction. After dropping the MgCl ₂ aqueous solution, the pH is 4.5 at 5.5.
The mixture was stirred under reflux at 100°C for an hour. After cooling this to 40℃, neutralize it with 1N sodium hydroxide solution, add 320g of table salt, and add 250g of toluene.
Extracted 4 times with ml. After drying the extract over anhydrous magnesium sulfate, toluene was distilled off under reduced pressure at 60°C to obtain 21.6 g of an oily substance. Next, this was distilled at 0.5 mmHg and 88 to 90℃ to obtain a 20.4
g of 4-hydroxy-4-methyl-5-allyl-2-cyclopentenone was obtained. Yield 85% Example 11 150 ml of water and 450 mg of tri-n-octyl-methyl-ammonium chloride were added, and 1/3N HCl
Adjust the pH to 5.5 with aqueous solution and 1/3N NaOH aqueous solution. Next, 11.0 g of 5-methyl-2-furyl-allyl-carbinol was added, the temperature was raised to 100°C, refluxed, and 1/3N NaOH aqueous solution and 1/3N HCl aqueous solution were added.
The mixture was stirred under reflux for 7 hours while maintaining the pH at 5 to 5.5. then 40
After cooling to ℃, add 30 g of common salt and extract 5 times with 70 ml of toluene. Toluene was distilled off at 60° C. under reduced pressure to obtain 10.1 g of oil. Next, this was developed using 100 g of silica gel with ethyl acetate-n-hexane (1 volume to 2 volumes) to obtain 7.1 g of the desired 4-hydroxy-4-methyl-5-allyl-2-cyclopentenone. Obtained. Yield 64.5%

Claims (1)

[Claims] 1. General formula [In the formula, R ₁ represents an alkyl group having up to 6 carbon atoms, an alkenyl group having up to 6 carbon atoms, an alkynyl group, or a group represented by the general formula [Formula] having no unsaturated bond at the bond end. R ₂ here represents a hydrogen atom, a methyl group or a halogen atom. ] The furancarbinol compound represented by is added in an aqueous solvent in the presence or absence of a catalyst at pH 3 to 6,
General formula characterized by processing at 20-120℃ [In the formula, R ₁ has the same meaning as above] A method for producing a 3-oxocyclopentene compound represented by the following. 2. The manufacturing method according to claim 1, wherein the catalyst is a metal salt and/or a surfactant.