Synthesis and biological activity of 8beta-substituted hydrocodone indole and hydromorphone indole derivatives.

The 8beta-unsubstituted and substituted analogues of hydrocodone indole and hydromorphone indole were synthesized and their binding affinities to opioid receptors were determined. Introduction of an 8beta-methyl group into the indolomorphinan nucleus increased affinity at all opioid receptors. 6,7-Dehydro-4,5alpha-epoxy-8beta-methyl-6,7,2',3'-indolomorphinan (9) was found to be a delta antagonist with subnanomolar affinity (0.7 nM) for the delta-opioid receptor, and to have good delta-selectivity (mu/delta=322).