Method for producing polyol-based esters of ketocarboxylic acids

A functionalized 3-oxobutyric acid polyglycerol ester,

• wherein the functionalized 3-oxobutyric acid polyglycerol ester corresponds to general formula (IIIb1″)
• R6O—CH2—CH(OR6)—CH2—[O—CH2—CH(OR6)—CH2]p—OR6 (IIIb1″)
• wherein, in the general formula (IIIb1″),
• the variable p represents an integer from 1 to 6,
• the radical R6, each independently of one another, identical or different, represents:
• hydrogen, CH3—C(O)—CH2—C(O)— or a radical R3, wherein the radical R3 represents a radical of the type linear or branched, saturated or mono- or polyunsaturated (C1-C33-alkyl)-C(O)—, however, with the proviso that at least one radical R6 does not represent hydrogen, and with the proviso that at least one radical R6 represents CH3—C(O)—CH2—C(O)—.

A method for producing polyglycerol esters of 3-oxobutyric acid,

• wherein at least one compound of general formula (I)
• CH3—C(O)—CH2—C(O)OR1 (I)
• wherein, in the general formula (I), the radical R1 represents C1-C4-alkyl,
• is reacted with at least one polyglycerol of general formula (IIb)
• HO—CH2—CH(OH)—CH2—[O—CH2—CH(OH)—CH2]p—OH (IIb)
• wherein, in the general formula (IIb), the variable p represents an integer from 1 to 6,
• wherein the reaction is carried out in the absence of solvents and
• wherein the reaction is carried out in the presence of an enzyme as a catalyst,
• wherein the enzyme catalyst is recycled after the reaction has been carried out,
• wherein the enzyme is used in amounts, based on the total amount of starting compounds (I) and (IIb), in the range of from 0.5% by weight to 10% by weight,
• wherein the reaction is carried out in the presence of an enzyme as a catalyst at temperatures in the range of from 50° C. to 70° C.,
• wherein the compound of the general formula (I), based on the hydroxyl groups of the polyglycerol (IIb), is used in a molar excess of up to 200 mol-%,
• so that, as a reaction product, one or more 3-oxobutyric acid polyglycerol esters are obtained,
• wherein, during reaction, a compound according to general formula (IV)
• R1—OH (IV)
• is formed simultaneously, wherein, in the general formula (IV), the radical R1 represents C1-C4 alkyl, wherein the compound according to the general formula (IV) is continuously withdrawn from the reaction,
• wherein hydroxyl groups still present in the reaction product after the reaction has taken place are at least partially functionalized via esterification at temperatures in the range of from 60 to 150° C. and
• in the absence of solvents,
• wherein the functionalization via esterification is carried out with at least one carboxylic acid anhydride of general formula (V)
• R3—O—R3 (V)
• wherein, in the general formula (V), the radical R3, each independently of one another, identical or different, represents a radical of the type linear or branched, saturated or mono- or polyunsaturated (C1-C33-alkyl)-C(O)—.