α-Amino acids and dioxopiperazines crowned at the α-carbons with polyether macrorings. Synthesis, complexation and self-assembling properties
Crowned α-amino acids 7a-c and their dioxopiperazine derivatives 12a-c were prepared from the easily accessible masked tris(hydroxymethyl)aminomethane 1. X-Ray crystal structures of the free as well as alkali metal ion coordinated compounds were investigated.