Catalytic Aerobic Oxidation of nor-Binaltorphimine (nor-BNI) Analogs without 4,5-Epoxy Bridge Affords a More Selective Ligand for .KAPPA. Opioid Receptor than the Representative .KAPPA. Antagonist nor-BNI
Catalytic Aerobic Oxidation of nor-Binaltorphimine (nor-BNI) Analogs without 4,5-Epoxy Bridge Affords a More Selective Ligand for .KAPPA. Opioid Receptor than the Representative .KAPPA. Antagonist nor-BNI
Catalytic Aerobic Oxidation of nor-Binaltorphimine (nor-BNI) Analogs without 4,5-Epoxy Bridge Affords a More Selective Ligand for .KAPPA. Opioid Receptor than the Representative .KAPPA. Antagonist nor-BNI
An analog of nor-binaltorphimine (nor-BNI) without the 4,5-epoxy bridge, 17,17′-bis(cyclopropylmethyl)-6,6′,7,7′-tetrahydro-6,6′-imino-14β,14′α-dihydroxy-3,3′-dimethoxy-7,7′-bimorphinan (4), which was the precursor of the designed compound 1 as a selective κ3 opioid receptor antagonist, was catalytically oxidized with oxygen in the presence of platinum to give the 5′-oxo derivative 3 with some other oxidized products. Morphinan derivatives without the 4,5-epoxy moiety were labile to oxygen, although the corresponding 4,5-epoxymorphinan derivatives resisted aerobic oxidation. One of the oxidized nor-BNI analogs without 4,5-epoxy bridge, compound 18, showed high affinity and selectivity for κ opioid receptor.