Enzymatic Dynamic Kinetic Resolution of Oxazinones: A New Approach to Enantiopure β 2 ‐Amino Acids

In the presence of Candida antarctica lipase B, the alcoholytic ring opening of 5‐substituted oxazinones proceeds as kinetic resolution (KR) and affords N ‐acyl β 2 ‐amino acid esters in up to 96 %  ee , the remaining oxazinones were obtained in up to 99 %  ee. In the presence of triethylamine as racemization catalyst, the enzyme‐catalyzed alcoholytic oxazinone opening proceeds as dynamic kinetic resolution (DKR), affording quantitative yields of N ‐protected β 2 ‐amino acid esters in high enantiomeric purity (up to 96 %  ee ). N,C‐double deprotection to afford the β 2 ‐amino acid can be effected without loss of enantiopurity.