2butenoates

2-Butenoates are a class of organic compounds that are esters of 2-butenoic acid. Also known as crotonic acid, 2-butenoic acid is an unsaturated carboxylic acid with the chemical formula C4H6O2. The double bond is located between the second and third carbon atoms, and the carboxyl group is at the first carbon. Because of the double bond, 2-butenoic acid exists as two geometric isomers: cis-2-butenoic acid (also known as angelic acid) and trans-2-butenoic acid (also known as crotonic acid). Consequently, 2-butenoates can be derived from either of these isomers, leading to angelic esters and crotonic esters, respectively.

These compounds are characterized by the presence of the ester functional group (-COO-) attached to a four-carbon chain containing a double bond at the second position. The general formula for a 2-butenoate is CH3CH=CHCOOR, where R represents an alkyl or aryl group. The physical and chemical properties of 2-butenoates vary depending on the nature of the R group. They are often liquids with characteristic odors and are used as intermediates in the synthesis of various chemicals, including polymers, pharmaceuticals, and fragrances. The reactivity of the double bond allows for addition reactions, while the ester group can undergo hydrolysis.