2-Hydroxy-3-methyl-2-cyclopenten-1-one
2-Hydroxy-3-methyl-2-cyclopenten-1-one is an organic compound related to 1,2-cyclopentanedione. It is the enol tautomer of the diketone 3-methylcyclopentane-1,2-dione. Being an enol, the compound is often called methylcyclopentenolone. It is a colorless solid.The compound is prepared by base-catalyzed condensation of 1‐hydroxyhexane‐2,5‐dione, a derivative of hydroxymethylfurfural.
The structure has been confirmed by X-ray crystallography.
Quantum calculations also indicate that the enol is strongly favored relative to the diketo tautomer. Furthermore, the enolization occurs at the methyl-substituted carbon.It is one of many products from the pyrolysis of lignocellulose.
It is used in flavors and perfumery for its maple- or caramel-like odor. It contributes to the flavor or odor of many foods including wines, coffee, paprika, and salmon. It is sometimes called maple lactone because it occurs in maple syrup.
