Method of producing 2-hydroxycarboxylic acid esters

A process for preparing 2-hydroxycarboxylic esters of the formula I

• in which
• R1 and R2 independently of one another are C1-C20-alkyl, C3-C8-cycloalkyl, C2-C20-alkenyl, C2-C20-alkynyl, C6-C10-aryl, C7-C14-aralkyl or C7-C20-alkylaryl, or R1 and R2 together with the carbon atom to which they are attached form a 5- to 8-membered ring;
• R3 is C1-C20-alkyl, C2-C20-alkenyl or C2-C20-alkynyl;
• R4 is C1-C20-alkyl, C3-C8-cycloalkyl, C2-C20-alkenyl, C2-C20-alkynyl, C6-C10-aryl, C7-C14-aralkyl or C7-C20-alkylaryl;
• which comprises reacting a glycidyl ester of the formula II
• in which R1, R2 and R4 are as defined above with an organoaluminum reagent of the formula III
• in which R3 is as defined above, X in each case independently have the meanings given for R3 or are halogen or C1-C4-alkoxy and n is from 0 to 10.