Method for synthesizing (S)(-)-gamma-lactone

Abstract

This invention discloses a method for synthesizing (S)-(-)-gamma-lactone. The method comprises: (1) using (R)-(+)-alpha-phenylethylamine as the chiral resolving agent, and reacting with racemic gamma-hydroxy acid to obtain a pair of diastereotopic salts; (2) separating by crystallization; (3) acidifying and cyclizing to obtain chiral (S)-(-)-gamma-lactone. (S)-(-)-gamma-lactone is (S)-(-)-gamma-decalactone, (S)-(-)-gamma-undercalactone or (S)-(-)-gamma-dodecalactone. (S)- (-)-gamma-lactone has special fragrance, and can be used to manufacture high-grade essence.

Description

Technical field:

[0001] The invention relates to a preparation method of chiral synthetic perfume, in particular to a synthesis method of (S)-(-)-γ-lactone. Background technique:

[0002] Natural lactone flavors are mostly found in the fruits of various fruits, such as γ-decalactone, γ-undecalactone, and γ-laurolactone, which are widely found in peaches, almonds, strawberries and other fruits. For example, the trade name of γ-undecalactone is also called peach aldehyde. They are all liquid in appearance and have a strong fruity aroma and milky aroma. They are widely used in the formulation of food flavors and daily cosmetic flavors. The chiral lactone after splitting has a purer and more natural style than the racemic lactone fragrance. For example: 4-(R)-(+)-γ-decalactone has a fresh peach flavor and can be used in fruit flavors. 4-(S)-(-)-γ-Decalactone can be used in dairy flavors. 4-(S)-(-)-γ-Undecalactone has a fatty feel and can be used in dairy flavors. 4-(S)-(-)...

Examples

Embodiment 1

[0007] In a 50 ml three-necked flask, 2.4 g (60 mmol) of sodium hydroxide was dissolved in 20 ml of water, and 6.8 g (40 mmol) of racemic gamma-decalactone was added dropwise at 60°C, and Stirring was continued at temperature for 2 hours. After cooling to room temperature, add 20 ml of ethyl acetate, then dropwise add 20% sulfuric acid to adjust the acidity to P H =5. Extract and separate the organic layer, and extract twice with ethyl acetate. The organic layers were combined, and 2.4 g (20 mmol) of (R)-(+)-α-phenethylamine was added. The solution was cooled at -15 to -30°C for 48 hours to obtain 2.5 g of white crystals. Dissolve the crystals in 10 ml of water and heat to 90°C. When all the solids are dissolved, dilute sulfuric acid is added to obtain a hydroxy acid, which is further cyclized into a lactone. Extracted with ethyl acetate, the organic layer was dried with anhydrous magnesium sulfate, (S)-(-)-γ-decalactone was obtained after removing the solvent, the yield w...

example 2

[0009] In a 1000 ml three-necked flask, 38.4 g (960 mmol) of sodium hydroxide was dissolved in 320 ml of water, and 108.8 g (640 mmol) of racemic gamma-decalactone was added dropwise at 60°C, and Stirring was continued at temperature for 2 hours. After cooling to room temperature, add 320 milliliters of ethyl acetate, then dropwise add 20% sulfuric acid to adjust the acidity to P H =5. The organic layer was separated and extracted twice with ethyl acetate. The organic layers were combined, 128 ml of methanol was added, and 38.7 g (320 mmol) of (R)-(+)-α-phenethylamine were added. The solution was cooled at -22°C for 18.5 hours to obtain 65.0 g of white crystals. Dissolve the crystals in 100 ml of water and heat to 90°C. When all the solids are dissolved, dilute sulfuric acid is added to obtain the hydroxy acid, which is further cyclized into a lactone. Extracted with ethyl acetate, the organic layer was dried with anhydrous magnesium sulfate, and (S)-(-)-γ-decalactone was ...

example 3

[0011] In a 1000 ml three-necked flask, 38.4 g (960 mmol) of sodium hydroxide was dissolved in 320 ml of water, and 108.8 g (640 mmol) of racemic gamma-decalactone was added dropwise at 60°C, and Stirring was continued at temperature for 2 hours. After cooling to room temperature, add 320 milliliters of ethyl acetate, then dropwise add 20% sulfuric acid to adjust the acidity to P H =5. The organic layer was separated and extracted twice with ethyl acetate. The organic layers were combined, 128 ml of methanol was added, and 38.7 g (320 mmol) of (R)-(+)-α-phenethylamine were added. The solution was cooled at -22°C for 67.5 hours to obtain 60.0 g of white crystals. The crystals were dissolved in 50 ml of water, heated to 80°C, and when the solid was completely dissolved, cooled to room temperature, and 55.0 g of solid was obtained by suction filtration.

[0012] Dissolve the recrystallized solid in an appropriate amount of water and heat to 90°C. When the solid is completely ...

Technical field:

[0001] The invention relates to a preparation method of chiral synthetic perfume, in particular to a synthesis method of (S)-(-)-γ-lactone. Background technique:

[0002] Natural lactone flavors are mostly found in the fruits of various fruits, such as γ-decalactone, γ-undecalactone, and γ-laurolactone, which are widely found in peaches, almonds, strawberries and other fruits. For example, the trade name of γ-undecalactone is also called peach aldehyde. They are all liquid in appearance and have a strong fruity aroma and milky aroma. They are widely used in the formulation of food flavors and daily cosmetic flavors. The chiral lactone after splitting has a purer and more natural style than the racemic lactone fragrance. For example: 4-(R)-(+)-γ-decalactone has a fresh peach flavor and can be used in fruit flavors. 4-(S)-(-)-γ-Decalactone can be used in dairy flavors. 4-(S)-(-)-γ-Undecalactone has a fatty feel and can be used in dairy flavors. 4-(S)-(-)...

Examples

Embodiment 1

[0007] In a 50 ml three-necked flask, 2.4 g (60 mmol) of sodium hydroxide was dissolved in 20 ml of water, and 6.8 g (40 mmol) of racemic gamma-decalactone was added dropwise at 60°C, and Stirring was continued at temperature for 2 hours. After cooling to room temperature, add 20 ml of ethyl acetate, then dropwise add 20% sulfuric acid to adjust the acidity to P H =5. Extract and separate the organic layer, and extract twice with ethyl acetate. The organic layers were combined, and 2.4 g (20 mmol) of (R)-(+)-α-phenethylamine was added. The solution was cooled at -15 to -30°C for 48 hours to obtain 2.5 g of white crystals. Dissolve the crystals in 10 ml of water and heat to 90°C. When all the solids are dissolved, dilute sulfuric acid is added to obtain a hydroxy acid, which is further cyclized into a lactone. Extracted with ethyl acetate, the organic layer was dried with anhydrous magnesium sulfate, (S)-(-)-γ-decalactone was obtained after removing the solvent, the yield w...

example 2

[0009] In a 1000 ml three-necked flask, 38.4 g (960 mmol) of sodium hydroxide was dissolved in 320 ml of water, and 108.8 g (640 mmol) of racemic gamma-decalactone was added dropwise at 60°C, and Stirring was continued at temperature for 2 hours. After cooling to room temperature, add 320 milliliters of ethyl acetate, then dropwise add 20% sulfuric acid to adjust the acidity to P H =5. The organic layer was separated and extracted twice with ethyl acetate. The organic layers were combined, 128 ml of methanol was added, and 38.7 g (320 mmol) of (R)-(+)-α-phenethylamine were added. The solution was cooled at -22°C for 18.5 hours to obtain 65.0 g of white crystals. Dissolve the crystals in 100 ml of water and heat to 90°C. When all the solids are dissolved, dilute sulfuric acid is added to obtain the hydroxy acid, which is further cyclized into a lactone. Extracted with ethyl acetate, the organic layer was dried with anhydrous magnesium sulfate, and (S)-(-)-γ-decalactone was ...

example 3

[0011] In a 1000 ml three-necked flask, 38.4 g (960 mmol) of sodium hydroxide was dissolved in 320 ml of water, and 108.8 g (640 mmol) of racemic gamma-decalactone was added dropwise at 60°C, and Stirring was continued at temperature for 2 hours. After cooling to room temperature, add 320 milliliters of ethyl acetate, then dropwise add 20% sulfuric acid to adjust the acidity to P H =5. The organic layer was separated and extracted twice with ethyl acetate. The organic layers were combined, 128 ml of methanol was added, and 38.7 g (320 mmol) of (R)-(+)-α-phenethylamine were added. The solution was cooled at -22°C for 67.5 hours to obtain 60.0 g of white crystals. The crystals were dissolved in 50 ml of water, heated to 80°C, and when the solid was completely dissolved, cooled to room temperature, and 55.0 g of solid was obtained by suction filtration.

[0012] Dissolve the recrystallized solid in an appropriate amount of water and heat to 90°C. When the solid is completely ...