Portal de Periódicos da CAPES

Amino acids and peptides. XXVIII. A new synthesis of .ALPHA.-amino acid derivatives by alkylation of Schiff bases derived from glycine and alanine.

1977; Pharmaceutical Society of Japan; Volume: 25; Issue: 9 Linguagem: Inglês

10.1248/cpb.25.2287

1347-5223

T. OGURI, Takayuki Shioiri, Shun‐ichi Yamada,

Chemical Reaction Mechanisms

The Schiff base (I) from glycine tert-butyl ester and benzaldehyde was treated with lithium diisopropylamide to give the corresponding α-carbanion. Alkylation of the α-carbanion with benzyl or butyl halide followed by removal of benzylidene group yielded phenylalanine or norleucine tert-butyl ester (IIa or IIb), accompanied by dialkylated product (IIIa or IIIb). The Schiff base (IV) from alanine tert-butyl ester and (-)-men-thone (VI) was also treated as above to furnish α-methylphenylalanine or α-methyl-β-(3, 4-dimethoxyphenyl) alanine tert-butyl ester (Va or Vb) in 21 or 24% asymmetric yield.