title: Synthesis of constrained analogues of cholecystokinin/opioid chimeric peptides.
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 β-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.
authors.forename: John M
authors.initials: JM
authors.lastname: Ndungu
authors.forename: James P
authors.initials: JP
authors.lastname: Cain
authors.forename: Peg
authors.initials: P
authors.lastname: Davis
authors.forename: Shou-W
authors.initials: SW
authors.lastname: Ma
authors.forename: Todd W
authors.initials: TW
authors.lastname: Vanderah
authors.forename: Josephine
authors.initials: J
authors.lastname: Lai
authors.forename: Frank
authors.initials: F
authors.lastname: Porreca
authors.forename: Victor J
authors.initials: VJ
authors.lastname: Hruby