Novel opiates and antagonists. 4. 7-Alkanoylhydromorphones

A series of 7-alkanoyl-substituted hydromorphone derivatives were prepared by acylation of the morpholine enamines. The most potent compound (6i) of the series was found to have agonist activity of the same order of magnitude as that of buprenorphine. The N-cyclopropylmethyl-substituted series was found to exhibit structure-activity relationships for analgesia and narcotic antagonism similar to those of the endo-ethanotetrahydrooripavines.