COORfunktionell

COORfunktionell is a term used in organic chemistry, particularly in German-language literature, to denote the ester functional group within a molecule. The COOR fragment represents a carbonyl carbon double-bonded to oxygen and single-bonded to an alkoxy oxygen, giving the general structure R–C(=O)–O–R′. This group defines esters and influences both reactivity and properties of the compound.

Structure and properties: The carbonyl carbon is electrophilic, making esters susceptible to nucleophilic attack. Resonance between the carbonyl oxygen and the adjacent alkoxy oxygen gives the C–O bonds partial double-bond character and contributes to the characteristic polarity of esters. Esters typically do not have acidic H on the carbonyl carbon and are generally less reactive toward nucleophilic substitution than carboxylic acids, though they readily undergo hydrolysis and transesterification under suitable conditions.

Reactions and transformations: Common reactions of COORfunktionell include hydrolysis to carboxylic acids and alcohols under acidic or basic conditions, known as saponification in basic media. Transesterification replaces the OR′ group with another alcohol, which is widely used in synthesis and polymer chemistry. Esters can also be reduced by strong reducing agents to give primary alcohols, and they can participate in various condensation and coupling reactions in organic synthesis.

Occurrence and applications: Esters are ubiquitous in nature and industry. They are key components of fats and oils (as glycerol triesters), fragrances and flavors, solvents, and polymers such as polyesters (for example PET). In synthesis, COORfunktionell groups often serve as protecting groups for carboxylic acids and as versatile intermediates that can be transformed into a wide range of products.

See also: ester, esterification, hydrolysis, transesterification, saponification.