SYNTHESIS OF ALPHA-AMINO-ACIDS BY RING-OPENING OF AZIRIDINE-2-CARBOXYLATES WITH CARBON NUCLEOPHILES

Excellent regiospecificity has been achieved in the reaction of carbon nucleophiles with N-para-toluenesulfonylaziridine-2-carboxylic acid ( 6, R = H) protected as the anion. This has been developed into a gener al and high yielding synthesis of optically pure alpha-amino acids con taining one chiral centre. When the aziridine (20) containing a second chiral centre was used, only lithium trimethylsilylacetylide gave the desired alpha-amino acid. Reaction with higher order cuprates gave lo wer yields, the principal products being the protected beta-amino acid s (22) and (23).