SEMISYNTHESIS OF C-20 H-3 RESINIFERATOXIN

There has recently been considerable interest concerning the biochemic al and pharmacological mechanisms of action of resiniferatoxin (Rx). R x is a daphnane diterpene ester, which is part of the phorbol ester fa mily of diterpenes. We have synthesized H-3-Rx in a three-step process from the parent alcohol, resiniferonol (Ro). The tritium label is inc orporated into the resiniferonol nucleus at the C-20 position, before esterification of H-3-Ro to H-3-Rx. This compound will be of use in th e elucidation of the binding characteristics of Rx to its biochemical receptor site(s).