Helvetica chimica acta

Versatile Stereoselective Synthesis of Completely Protected Trifunctional α??Methylated α??Amino Acids Starting from Alanine

E Altmann, K Nebel, M Mutter

Index: Altmann, Eva; Nebel, Kurt; Mutter, Manfred Helvetica Chimica Acta, 1991 , vol. 74, # 4 p. 800 - 806

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Citation Number: 50

Abstract

Abstract A new route to completely protected α-methylated α-amino acids starting from alanine is described (see Scheme). These derivatives, which are obtained via base- catalyzed opening of the oxazolidinones (2S, 4R)-and (2R, 4S)-2, can be directly employed in peptide synthesis. The synthesis of both enantiomers of Z-protected α-methylaspartic acid β-(tert-butyl) ester (O 4-(tert-butyl) hydrogen 2-methylaspartates (R) or (S)-4a), α-methyl- ...