text: There have been a number of reported procedures which take advantage of a chemical reagent/catalyst to perform racemization of the starting material and an enzyme to selectively react with one enantiomer, called chemoenzymatic dynamic kinetic resolutions. PSL-C was utilized along with a ruthenium catalyst (for racemization) to produce enantiopure (>95% ee) δ-hydroxylactones. 
  More recently, secondary alcohols have been resolved by Bäckvall with yields up to 99% and ee's up to >99% utilizing CALB and a ruthenium racemization complex. 
  A second type of chemoenzymatic dynamic kinetic resolution involves a π-allyl complex from an allylic acetate with palladium. Here, racemization occurs with loss of the acetate, forming a cationic complex with the transition metal center, as shown below. Palladium has been shown to facilitate this reaction, while ruthenium has been shown to affect a similar reaction, also shown below.