Semi-synthesis of C20 3H-resiniferatoxin

There has recently been considerable interest concerning the biochemical and pharmacological mechanisms of action of resiniferatoxin (Rx). Rx is a daphnane diterpene ester, which is part of the phorbol ester family of diterpenes. We have synthesized ³H-Rx in a three-step process from the parent alcohol, resiniferonol (Ro). The tritium label is incorporated into the resiniferonol nucleus at the C₂₀ position, before esterification of ³H-Ro to ³H-Rx. This compound will be of use in the elucidation of the binding characteristics of Rx to its biochemical receptor site(s).