Quaternary α-Amino Acids and Derivatives

Significance

Racemic oxazolones 1 are used as masked amino acid fragments and employed in a diastereo- and enantioselective nucleophilic addition to α,β-unsaturated aldehydes 2. The reaction is catalyzed by commercially available diarylprolinol silyl ether 3 and yields α,α-disubstituted α-amino acid derivatives with two new chiral centers in a one-step synthesis.