N-Substituted 2-Amino-4-pentenoic Acids for Amino Acid Protection and Resolution

N-Substituted 2-amino-4-pentenoic acid derivatives employed for the protection of racemic amino acids were shown to be capable of permitting the chromatographic separation of R and S isomers. When Nα was disubstituted with benzyl and phenylfluorenyl groups, the racemic amino acids could be separated with facility on open silica gel columns. Further, the optically pure N-protected amino acids so derived could be used for the preparation of misacylated suppressor transfer RNAs.