Resolution of 2-alkanols by microbially-catalyzed esterification

A method based on the use of whole lyophilized microbial cells has been developed for resolution of 2-alkanols. Firstly, the esterification of racemic 2-octanol with butyric acid was studied. Rhizopus oryzae CBS 112-07 grown on Tween 80 was selected as a suitable biocatalyst. Appropriate choice of solvent, temperature and reactant concentration allowed for highly selective esterification (>97% enantiomeric excess of R-ester, 41% molar conversion). Direct esterification of 2-octanol with butyric acid was compared with interesterification using different acylating reagents. The best results were obtained with butyric acid and tributyrin. Esterification of other racemic 2-alkanols (2-butanol, 2-pentanol, 2-hexanol, 2-heptanol) showed that chain length played a crucial role in enantioselectivity, since lower enatiomeric excesses were observed using short chain alcohols. A method based on the use of whole lyophilized microbial cells has been developed for resolution of 2-alkanols. Firstly, the esterification of racemic 2-octanol with burytic acid was studied. Rhizopus oryzae CBS 112-07 grown on Tween 80 was selected as a suitable biocatalyst. Appropriate choice of solvent, temperature and reactant concentration allowed for highly selective esterification (>97% enantiomeric excess of R-ester, 41% molar conversion). Direct esterification of 2-octanol with butyric acid was compared with interesterification using different acylating reagents. The best results were obtained with butyric acid and tributyrin. Esterification of other racemic 2-alkanols (2-butanol, 2-pentanol, 2-hexanol, 2-heptanol) showed that chain length played a crucial role in enantioselectivity, since lower enatiomeric excesses were observed using short chain alcohols.