Highly enantioselective production of (R)-halohydrins with whole cells of Rhodotorula rubra KCh 82 culture

Abstract

Biotransformation of ten α-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.