Synthesis of quinolinomorphinan-4-ol derivatives as δ opioid receptor agonists

The morphinan derivatives with the 4-hydroxy group (SN-24, 26, 27) showed higher selectivities for the δ receptor over the μ receptor than the corresponding derivatives with the 3-hydroxy group. And they showed high agonist activities for the δ receptor in the [35S]GTPγS binding assay.