Preparation of .beta.-hydroxycarboxylates

Abstract

A process for the preparation of .beta.-hydroxycarboxylates of the general formula I ##STR1## in which R.sup.1 and R.sup.2 individually denote C.sub.1 -C.sub.20 alkyl optionally substituted by C.sub.1 -C.sub.8 alkoxy and/or halogen, C.sub.3 -C.sub.20 alkoxycarbonylalkyl, C.sub.2 -C.sub.20 alkenyl, C.sub.5 -C.sub.30 acetalalkenyl, aryl optionally mono- to penta-substituted by C.sub.1 -C.sub.8 alkyl, C.sub.1 -C.sub.8 alkoxy, and/or halogen, C.sub.7 -C.sub.20 aralkyl, C.sub.7 -C.sub.20 aralkenyl, hetaryl, C.sub.3 -C.sub.20 cycloalkyl, or C.sub.4 -C.sub.20 cycloalkylalkyl, or together denote a C.sub.2 -C.sub.8 alkylene chain and one or other of R.sup.1 and R.sup.2 denotes hydrogen, and R.sup.3 denotes hydrogen, C.sub.1 -C.sub.20 alkyl, C.sub.2 -C.sub.20 alkenyl, aryl optionally mono- to penta-substituted by C.sub.1 -C.sub.8 alkyl, C.sub.1 -C.sub.8 alkoxy, and/or halogen, C.sub.7 -C.sub.20 aralkyl, C.sub.3 -C.sub.20 cycloalkyl, or C.sub.4 -C.sub.20 cycloalkylalkyl, and R.sup.4 denotes C.sub.1 -C.sub.20 alkyl, C.sub.4 -C.sub.20 alkenyl, C.sub.7 -C.sub.20 aralkyl, C.sub.3 -C.sub.20 cycloalkyl, or C.sub.4 -C.sub.20 cycloalkylalkyl, by the reaction of carbonyl compounds of the general formula II ##STR2## in which R.sup.1 and R.sup.2 have the meanings stated above, with .alpha.-bromocarboxylates of the general formula III ##STR3## in which R.sup.3 and R.sup.4 have the meanings stated above, wherein the reaction with zinc is carried out in methylene chloride at a temperature ranging from 0.degree. to 50.degree. C.

Dependencies are inferred from the claim text.