Asymmetric synthesis of α-methyl α-amino acids by diastereoselective alkylation of optically active 6-isopropyl-3-methyl-2,3-dihydro-6H-1,4-oxazin-2-ones

Article abstract of DOI:10.1002/anie.199709951

At room temperature already highly diastereoselective alkylation of the new, cyclic, chiral alanine ester derivatives (6R)-1 can be achieved with either K₂CO₃ as base under solid liquid phase-transfer catalysis or Pd catalysis under neutral conditions. The products (3S,6R)-2 can be easily hydrolyzed to form (S)-α-methyl α-amino acids.