International Journal of Molecular Sciences, Vol.15, No.12, 22392-22404, 2014
Highly Enantioselective Production of (R)-Halohydrins with Whole Cells of Rhodotorula rubra KCh 82 Culture
Biotransformation of ten alpha-haloacetophenones in the growing culture of the strain Rhodotorula rubra KCh 82 has been carried out. Nine of the substrates underwent an effective enantioselective reduction to the respective (R)-alcohols according to Prelog's rule, with the exception of 2-chloro-1,2-diphenylethan-1-one that was not transformed by this strain. The expected reduction proceeded without dehalogenation, leading to the respective (R)-halohydrins in high yields. The use of this biocatalyst yielded (R)-2-bromo-1-phenylethan- 1-ol (enantiomeric excess (ee) = 97%) and its derivatives: 4'-Bromo-(ee = 99%); 4'-Chloro-(ee > 99%); 4'-Methoxy-(ee = 96%); 3'-Methoxy-(ee = 93%); 2'-Methoxy( ee = 98%). There were also obtained and characterized 2,4'-dichloro-, 2,2', 4'-trichloro-and 2-chloro-4'-fluoro-phenyetan-1-ol with > 99% of enantiomeric excesses.
Keywords:enantiospecific reduction;beta(2)-adrenoceptor-stimulating agent;(R)-halohydrins;Rhodotorula rubra