Asymmetric Meerwein-Ponndorf-Verley reduction of long chain keto alkanoic acid methyl esters

Abstract

3-, 7- and 13-Monoketo tetradecanoic acid methyl esters carrying a keto group at the ends and at the middle of the chain with 14 carbon atoms were reduced by a Meerwein-Ponndorf-Verley reaction in the presence of R-(+)-1,1'-binaphthalcne-2,2'-diol, 1,2:5,6-D-di-O-isopropylidene-D-mannitol and L-(-)-menthol. The highest enantiomeric purity of 65% ee was found for 13-hydroxy ester isomer. The enantiomeric excess was determined by H-1-NMR shift with Eu(tfc)(3) and by optical rotation.