(S)-2-Amino-6-(aminooxy)hexanoic acid (AAHA, 3), a non-proteinogenic amino
acid, and its derivative, (S)-(-)-6-{[(tert-butoxycarbonyl)amino]oxy}-2-{[(
9H-fluoren-9-ylmethoxy)-carbonyl]amino}hexanoic acid (4), were synthesized
from (S)-(-)-6-amino-2-{[(benzyloxy)carbonyl] amino}hnoic acid (5) in good
overall yield.