Enantioselective benzylic microbial hydroxylation of indan and tetralin

A screening with 15 strains of bacteria and fungi targeted at the production of specific hydroxylated benzylic derivatives of indan 1 and tetralin 2 was carried out. Mortierella isabellina, Mortierella ramanniana and Beauveria bassiana were shown to mediate the respective conversions to 1-indanol (3) and 1-tetralol (4), the most satisfactory results being obtained with M. isabellina, which gave 78% conversion of 1 to (1R)-3 (64% yield, 86% ee) after a 2-day-incubation, and 52% conversion of 2 to (1R)-4 (38% yield, 92% ee) in a 4-day-incubation. Over-oxidation of alcohols 3 and 4 during the reactions resulted on the formation of 1-indanone and 2-tetralone, respectively.