Synthesis of Novel Chiral Calix[4]crown: Lariat Calix[4]-1,3-aza-crown with Chiral Amino Acid Group as Branched Chain

The novel lariat calix[4]-1,3-aza-crowns with chiral amino acids groups as branched chain (5a) and (5b) were synthesized via “1+1” addition of calix[4]-1,3-substituted benzaldehyde derivative (4) and amino acids hydrazide derivatives (3a) and (3b) in yields of 70% and 75%, respectively.