RESOLUTION OF 2-METHYLALKANOIC ACIDS - ENANTIOSELECTIVE ESTERIFICATION WITH LONG-CHAIN ALCOHOLS CATALYZED BY CANDIDA-RUGOSA LIPASE

Candida rugosa lipase catalysed resolutions of 2-methylalkanoic acids run on a large scale often display decreased enantiomeric rations (E-v alues) and reaction rates compared with small-scale experiments. By co ntinuous control of the water activity (addition of inorganic salt/hyd rated salt mixtures) this can be avoided. The importance of the proper choice of alcohol as well as its concentration is demonstrated. (R)-2 -Methyloctanoic acid (8.6g) and (S)-2-methyl-l-octanol (4.5 g), both i n 99.6% ee were prepared from 20 g racemic 2-methyloctanoic acid.