Methods for disproportionation quenching of ozonides
The present disclosure provides improved methods of performing ozonolysis on alkenes comprising non-reductive quenching of ozonide intermediates using Bronsted bases to yield aldehyde, ketone and/or carboxylic acid products.
1. A method of non-reductive quenching of ozonides using Bronsted bases to yield aldehyde and carboxylic acid, or ketone and carboxylic acid products, wherein the method comprises (a) reacting an alkene with ozone to generate a secondary ozonide intermediate, and (b) quenching the ozonide by adding an alkali metal or alkaline earth metal hydroxide, carbonate, bicarbonate, sulfate or phosphate to the ozonide in a C 2 -C 12 carboxylic acid solvent with water co-solvent to form the corresponding alkali metal or alkaline earth metal salt of the C 2 -C 12 carboxylate salt Bronsted base in-situ, to yield the aldehyde and carboxylic acid products, or the ketone and carboxylic acid products; and
wherein step (b) does not comprise a reducing agent and/or an oxidizing agent.
2. The method of claim 1 , wherein the C 2 -C 12 carboxylic acid solvent is a C 2 -C 12 saturated carboxylic acid.
3. The method of claim 1 , wherein the alkali metal or alkaline earth metal hydroxide, carbonate, bicarbonate, sulfate or phosphate added in step (b) is an alkali metal or alkaline earth metal hydroxide.
4. The method of claim 3 , wherein the alkali metal or alkaline earth metal hydroxide is selected from the group consisting of sodium hydroxide, potassium hydroxide, calcium hydroxide, and magnesium hydroxide.
5. The method of claim 1 , wherein step (b) occurs at a temperature from 30 to 100° C., optionally, wherein said temperature is between 50 and 90° C. or between 50 and 80° C.
6. The method of claim 1 , wherein the method further comprises isolating or purifying an aldehyde product and a carboxylic acid product, or a ketone product and a carboxylic acid product, from the quenching step (b).
7. The method of claim 1 , wherein the alkene is a monounsaturated fatty acid or ester.
8. The method of claim 1 , wherein the alkene is a terpene.
9. The method of claim 8 , wherein the terpene is selected from pinenes, camphenes, citronellol, citronellal, isopulegol, longifolene, isothujone and thujone.
10. The method of claim 1 , wherein the alkene is oleic acid, ricinoleic acid, erucic acid, or any esters thereof.
11. The method of claim 1 , wherein the secondary ozonide is a monosubstituted, disubstituted, or trisubstituted ozonide, and the products comprise aldehyde or ketone product and carboxylic acid product.