Levulinic acid (LA) – preparation and application

General description and preparation:

Levulinic acid, or 4-oxo-pentanoic acid, or b-acetylpropionic acid, or g-ketovaleric acid [123-76-2] is an organic acid belonging to keto acids group. In its pure form, it is a white crystalline solid with melting point of 33 °C.^[1] It is soluble in water and polar organic solvents. Despite its low toxicity (LD₅₀ 1850 mg/Kg, oral, rat), as other acids, it can cause the acid burns and high concentrated solutions are irritating to the skin and mucous membranes.^[2] The name, levulinic acid (originally levulinsäure, in german) was suggested by A. v. Grote and B. Tollens in 1874 as it was prepared from L-sugar (L-fructose) known as levulose.^[3]

Levulinic acid can be produced by acid hydrolysis of 5-hydroxymethylfufural (5-HMF), or by transformation of biomass/cellulose via formation of monomeric sugar derivatives.^[4] In 1953 Quaker Oats developed a continuous process to produce levulinic acid from carbohydrate material such as starch, cellulose, or sugars.^[5]

Application of Levulinic acid:

It can be used as a raw material in organic synthesis, especially in the production process of some pharmaceuticals, in the preparation of 5-methyl-2-pyrrolidone,^[6] g-valerolactone^[7] and angelica lactone.^[8] It has been recently found to be useful in the production of plasticizers and its esters as fragrance ingredients (fraistone) are used in the cosmetics production.^[9] LA was identified as one of the twelve promising bio-based building blocks that can be subsequently converted to a number of high-value chemicals, fuels or materials.^[10]

Product categorization (Chemical groups):

Main category:

• Carboxylic acids / salts
• Ketones / Ketals / Aminals

Second level:

• Aliphatic compounds

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