Synthesis of New ß-Amino Acids via 5-Oxazolidinones and the Arndt–Eistert Procedure

N-Methyl ß-amino acids are potentially useful amino acid derivatives for incorporation in lead peptide therapeutics. The syntheses of five such compounds are presented. Their synthesis via 6-oxazinanones was low yielding. Alternatively, reductive cleavage of a 5-oxazolidinone gave the N-methyl a-amino acid, which was then homologated via an Arndt–Eistert procedure in high yield to give the N-methyl ß-amino acid.