CH2CHCOOR

CH2CHCOOR denotes an α,β-unsaturated ester fragment, most commonly written in practice as CH2=CH-COOR. In this representation, a vinyl group (CH2=CH-) is conjugated to a carbonyl carbon of an ester (COOR), creating an electron-poor, conjugated system known for its reactivity as a Michael acceptor. The R in COOR is an alkyl or aryl group, and the OR' portion is the alkoxy substituent of the ester.

The fragment is a key motif in organic synthesis and polymer chemistry. It is typically prepared by esterification of acrylic acid with the chosen alcohol (ROH) or by transesterification of related esters. Acrylates are widely used due to the reactivity of the vinyl group and the stability of the ester moiety. In addition, derivatives can be produced by functionalizing the ester or the vinyl carbon.

Reactivity and notable properties include conjugate (1,4-) additions to the β-carbon by nucleophiles, which is a hallmark of α,β-unsaturated carbonyl compounds. The vinyl group also enables radical and ionic polymerizations, leading to polyacrylates and related materials. Hydrolysis or transesterification can modify the ester substituent, altering physical properties or reactivity in subsequent steps. Some substituted acrylates may exhibit stereochemical considerations at the double bond if additional substituents are present beyond the terminal vinyl group; however, the common CH2=CH-COOR motif is terminal and lacks E/Z isomerism.

Applications span coatings, adhesives, paints, and various polymeric materials. Safety and handling depend on the specific ester; acrylates can be irritants and require appropriate controls to manage polymerization risks and exposure.