bentley compounds bentley compounds the bentley compounds are a class of semi-synthetic opioids that were first synthesized by k. w. bentley by diels-alder reaction of thebaine with various dienophiles. the compounds are also known as thevinols, orvinols, or bridged oripavine derivatives, due to the characteristic 6,14-endo-ethano- or etheno-bridge and substitution at the 7α position. buprenorphine and etorphine are perhaps the best known of the family, which was the first series of extremely potent μ-opioid agonists, with some compounds in the series having over many thousands of times the analgesic potency of morphine. general structure of a bentley compound with an ethano-bridge (single bond) general structure of a bentley compound with an etheno-bridge (double bond)