9undecenoic

9undecenoic acid, also known as undecylenic acid, is an unsaturated fatty acid with the chemical formula CH2=CH(CH2)8COOH. It is a straight-chain monounsaturated carboxylic acid with a terminal double bond at the ninth carbon atom from the carboxyl group. Naturally occurring in the essential oil of the castor bean plant (Ricinus communis), it is primarily derived from the pyrolysis of ricinoleic acid, the main component of castor oil.

This compound is a colorless to pale yellow oily liquid with a characteristic odor. It is sparingly soluble in water but soluble in many organic solvents such as ethanol and ether. 9undecenoic acid and its derivatives, particularly its salts and esters, exhibit antifungal properties, making them useful in pharmaceutical and cosmetic applications. They are commonly found in over-the-counter treatments for fungal skin infections like athlete's foot and ringworm. Additionally, 9undecenoic acid serves as a precursor in the synthesis of various polymers, fragrances, and other chemical intermediates. Its chemical structure, with both a reactive double bond and a carboxylic acid group, allows for a range of chemical transformations.