Substrate modification as a means of enhancing the enantioselectivity of microbial reductions of β-keto esters. An (R)- or (S )-1,3,5-trihydroxypentane synthon

Article abstract of DOI:10.1021/jo00378a007

The enantioselectivity of yeast-mediated reduction of 5-(benzyloxy)-3-oxopentanoate esters can be optimized by simple selection of a suitable ester alkoxy group. The resulting chiral 5-(benzyloxy)-3-hydroxypentanoates with > 95% ee can serve as either an (R)- or (S)-1,3,5-trihydroxypentane synthon for asymmetric syntheses. The synthesis of a key optically active intermediate for (S)-(-)-lipoic acid is provided as an example.