Levoglucosenone is an organic compound with the formula . A pale yellow liquid, it is an unsaturated bicyclic

ketone In organic chemistry, a ketone is a functional group with the structure R–C(=O)–R', where R and R' can be a variety of carbon-containing substituents. Ketones contain a carbonyl group –C(=O)– (which contains a carbon-oxygen double bo ...

-diether formed from levoglucosan by loss of two molecules of water. As a product of the acid-catalysed pyrolysis of cellulose, _D-glucose, and levoglucosan, this liquid hydrocarbon is of interest as a biofuel and biofeedstock.

Production

The compound was first identified in 1970 as a product of the thermal decomposition of cellulose. Cellulose-Pyrolyse zu LGO

The primary way of obtaining levoglucosenone is via pyrolysis of

carbohydrates In organic chemistry, a carbohydrate () is a biomolecule consisting of carbon (C), hydrogen (H) and oxygen (O) atoms, usually with a hydrogen–oxygen atom ratio of 2:1 (as in water) and thus with the empirical formula (where ''m'' may or may ...

, particularly cellulose. Levoglucosenone can be derived from biomass or from other cellulosic materials including domestic/commercial waste paper. The availability of multiple sources is a key advantage when compared to other platform chemicals which are solely derived from biomass. The title compound is produced when cellulose is heated above 170 °C with

sulfuric acid Sulfuric acid (American spelling and the preferred IUPAC name) or sulphuric acid ( Commonwealth spelling), known in antiquity as oil of vitriol, is a mineral acid composed of the elements sulfur, oxygen and hydrogen, with the molecular formu ...

with various additives. Alongside levoglucosenone as a major product, 2-furfuraldehyde is sometimes formed in 5-10%. The bio-oil can be vacuum distilled, resulting in purified levoglucosenone. The use of polar, aprotic solvents such as THF, γ-valerolactone and sulfolane has been found to improve pyrolytic yields, as the solvents cause swelling of the cellulose and inhibit repolymerisation back to levoglucosan. These solvents also promote catalytic dehydration of levoglucosan to levoglucosenone. Microwave irradiation of microcrystalline cellulose can also be used to produce levoglucosenone. Hydrierung_von_LGO_zu_Dihydrolevoglucosenon

Hydrierung_von_LGO_zu_Dihydrolevoglucosenon

Cellulose-containing waste from biorefineries can also be converted into 6-8% LGO under microwave irradiation in addition to the usual decomposition products such as hydroxymethylfurfural HMF,

formic acid Formic acid (), systematically named methanoic acid, is the simplest carboxylic acid, and has the chemical formula HCOOH and structure . It is an important intermediate in chemical synthesis and occurs naturally, most notably in some ants. Es ...

, formaldehyde, CO₂ and water.

Reactions

As a highly functionalized, chiral compound, levoglucosenone is a precursor to a variety of compounds. Levoglucosenone is a promising bio-renewable platform for the production of commodity chemicals, being especially interesting the new insight provided by Huber and co-workers into how to transform this molecule into α,ω-diols, monomers for the production of polyesters and polyurethanes.

Palladium on carbon Palladium on carbon, often referred to as Pd/C, is a form of palladium used as a catalyst. The metal is supported on activated carbon to maximize its surface area and activity. Uses Hydrogenation Palladium on carbon is used for catalytic hydrog ...

(and related Pd- and Pt-based catalysts) act on the title compound by hydrogenation (i.e. dihydrolevoglucosenone and levoglucosanol) and hydrogenolysis (i.e. tetrahydrofurandimethanol (THFDM) and 1,6-hexanediol). Levoglucosenone is a Michael acceptor enabling its conversion to a variety of derivatives.

References

{{reflist Enones Oxygen heterocycles

Production

Reactions

See also

References