1.
Tetrahedron Lett
; 47(13): 2233-2236, 2006 Mar 27.
Article
in English
| MEDLINE
| ID: mdl-17203138
ABSTRACT
In our ongoing research on the synthesis of constrained analogues of CCK/opioid chimeric peptides, a bicyclic dipeptide mimetic for Nle-Asp was designed and synthesized. Starting from ß-allyl substituted aspartic acids, the terminal double bond was oxidized resulting in spontaneous cyclization to form racemic hemiaminals. Allylation of the hemiaminals afforded 5-allyl substituted proline analogues, which on oxidation, Horner-Emmons olefination, asymmetric hydrogenation, and bicyclization afforded bicyclic dipeptide mimetics for Nle-Asp. Constrained CCK/opioid peptide analogues containing bicyclic dipeptide mimetics for Nle-Gly, Nle-Asp, and homoPhe-Gly were then synthesized and analyzed at both the CCK and opioid receptors.