Beschreibung:
<jats:title>Abstract</jats:title><jats:p>A chemo‐ and biocatalytic cascade approach was applied for the stereoselective synthesis of hydroxy ketones and the corresponding 1,3‐diols. A new class of tridentate N,N,O ligands was used with copper(II) complexes for the asymmetric β‐borylation of α,β‐unsaturated compounds. The complex containing ligand <jats:bold>L5</jats:bold> emerged as the best performer, and it gave the organoborane derivatives with good <jats:italic>ee</jats:italic> values. The corresponding keto–alcohol compounds were then bioreduced by yeasts. The biotransformation set up with <jats:italic>Rhodotorula rubra</jats:italic> allowed (<jats:italic>R</jats:italic>)‐keto–alcohols and (<jats:italic>S</jats:italic>,<jats:italic>S</jats:italic>)‐diols to be obtained with up to 99 % <jats:italic>ee</jats:italic> and up to 99 % <jats:italic>de</jats:italic> in favor of the <jats:italic>anti</jats:italic> enantiomers.</jats:p>