Lipase catalyzed asymmetrization of quinolyl substituted 1,3-propanediols

Abstract

2-(2-Quinolyl)- and 2-(4-quinolyl)-1,3-propanediols 3 and 4 were prepared and asymmetrized by enantioselective acetylation in organic solvent catalyzed by lipases. While monoacetate 5 was best obtained using Celite-supported pig pancreatic lipase (PPL) (97.3% e.e.) as the ( R)-enantiomer, both enantiomers of 6 have been obtained using different enzymes: ( R)- 6 using lipase from Aspergillus niger (84.0% e.e.) and ( S)- 6 using lipase from Candida antarctica (97.5% e.e.). The absolute configuration of both monoacetates 5 and 6 has been determined by anomalous X-ray dispersion methodology on the corresponding p-bromobenzoates 11 and 12.