Enantiopure N‐Benzyloxycarbonyl‐β2‐amino Acid Allyl Esters from Racemic β‐Lactams by Dynamic Kinetic Resolution using Candida antarctica Lipase B

The dynamic kinetic resolution of α‐substituted racemic β‐lactams by alcoholytic ring‐opening, catalyzed by immobilized lipase B from Candida antarctica is described. With this process, a variety of racemic α‐substituted N‐Cbz‐azetidinones (Cbz=benzyloxycarbonyl) was transformed to the corresponding N‐Cbz‐protected β²‐amino acid allyl esters with high enantioselectivity (up to 99%) and high yields (up to quantitative) at room temperature.