Segment Coupling to a Highly Hindered N-Terminal, Alamethicin-Related alpha-Aminoisobutyric Acid (Aib) Residue.
A model [6 + 5] segment coupling process involving a C-terminal valine hexapeptide acid and a resin-attached pentapeptide amide which N-terminated in a hindered Aib unit was examined using a variety of HOAt-derived coupling reagents. Best results were observed with HAPyU in DCM solvent in which loss of configuration amounted to 5.8%.
Department of Chemistry, University of Massachusetts, Amherst MA 01003, USA.
Louis A
LA
Carpino
Adel Ali
AA
Abdel-Maksoud
E M E
EM
Mansour
Mohamed A
MA
Zewail