Optically active 3-amino-2H-azirines as synthons for enantiomerically pure α,α-disubstituted α-amino acids: Synthesis of the α-methylphenylalanine synthons and some model peptides

Article abstract of DOI:10.1002/hlca.19950780416

The synthesis of a novel 2-benzyl-2-methyl-3-amino-2H-azirine derivative with a chiral amino group is described. Chromatographic separation of the diastereoisomer mixture yielded the pure diastereoisomers 9a and 9b which are the D- and L-2-methylphenylalanine ((α-Me)Phe) synthons, respectively. The reaction of 9a and 9b with thiobenzoic acid and with Z-leucine yielded the monothiodiamides 10a and 10b and the dipeptide derivatives 11a and 11b, respectively. Methanolysis of 11b yielded 12b. The absolute configuration of 10a was established by X-ray crystallography. The absolute configuration of (α-Me)Phe in 12b has been deduced from the known configuration of L-leucine.