Process for preparing conjugated linoleic acid and derivatives thereof from ricinoleic acid
A process for preparing conjugated linoleic acid (CLA) or derivatives thereof from ricinoleic acid, lower alkyl esters of ricinoleic acid, or salts thereof. The CLA is formed by reacting a carboxylic acid, or anhydride, anhydride equivalent, or ester thereof with the ricinoleic acid or derivative to form an intermediate having a carboxylic ester at the 12-hydroxy position of the ricinoleic acid or derivative, and reacting the intermediate with a base to form a cis-9, trans-11 conjugated linoleic acid.
1. A process for producing a conjugated linoleic acid or an ester thereof comprising the steps of:
(a) reacting a ricinoleic acid or ester or salt thereof with a carboxylic acid, a carboxylic ester, or a carboxylic anhydride, or a carboxylic derivative that has a leaving group attached to the carbonyl moiety and facilitates an acylation reaction to form an acylated intermediate comprising a carboxylic ester at the 12-hydroxy position of the ricinoleic acid or ester or salt thereof;
(b) reacting the intermediate with a base to remove the carboxylic ester at the 12-hydroxy position from the ricinoleic acid or ester or salt thereof to form a conjugated linoleic acid or an ester thereof.
2. The process of claim 1 , wherein the base is an alkali or alkaline earth alkoxide salt of a C 1 -C 4 alkyl group alcohol.
3. The process of claim 1 , wherein the base is an amine.
4. The process of claim 2 , wherein the cation of the alkoxide salt is sodium, potassium or calcium.
5. The process of claim 2 , wherein the base is a solid.
6. The process of claim 2 , wherein the base is in solution in the alcohol of the alkoxide salt.
7. The process of claim 1 , wherein the base is added to the intermediate at a temperature in the range of about 80° C. to about 160° C.
8. The process of claim 7 , wherein the temperature is in the range of about 80° C. to about 140° C.
9. The process of claim 8 , wherein the temperature is about 90° C.
10. The process of claim 3 , wherein the amine is 1,8,-diazabicyclo [5.4.0] undec-7-ene or 1,5,7,-triazabicyclo [4.4.0] dec-5-ene.
11. The process of claim 1 , wherein the base is an inorganic or an alkyl ammonium hydroxide.
12. The process of claim 11 , wherein the inorganic hydroxide cation is sodium, potassium or calcium.
13. The process of claim 11 , wherein the alkyl ammonium cation is selected from the group consisting of symmetrical tetra C 1 -C 4 alkyl, benzyl tri C 1 -C 4 alkyl, dibenzyl di C 1 -C 4 alkyl, and C 12 -C 18 alkyl, tri C 1 -C 4 alkyl ammonium groups.
14. The process of claim 1 , wherein the intermediate is formed by reacting a C 2 -C 10 carboxylic anhydride or a C 2 -C 10 carboxylic derivative that has a leaving group attached to the carbonyl moiety that facilitates an acylation reaction with the ricinoleic acid or ester or salt thereof.
15. The process of claim 14 , wherein the reaction to form the intermediate takes place in a solvent.
16. The process of claim 14 , wherein the C 2 -C 10 carboxylic derivative is a carboxylic derivative having a halide, carbonate, heteroatom or imidazole leaving group.
17. The process of claim 1 , wherein the intermediate is formed by reacting a C 2 -C 10 carboxylic acid with the ricinoleic acid or ester or salt thereof.
18. The process of claim 1 , wherein the intermediate is formed by reacting an ester of a C 2 -C 10 carboxylic acid with the ricinoleic acid or ester or salt thereof.
19. The process of claim 18 , wherein the reaction to form the intermediate is catalyzed by a base.
20. The process of claim 19 , wherein the base catalyst is an alkali or alkaline earth alkoxide salt.
21. The process of claim 20 , wherein the cation of the alkoxide salt is selected from the group consisting of sodium, potassium and calcium.
22. The process of claim 18 , wherein the ester is a C 2 -C 10 alkyl ester of a C 2 -C 10 carboxylic acid.