Efficient synthesis of [2H2]-tetrahydrodicranenone B and a 3-oxa-analogue resistant against β-oxidation

A short efficient synthesis of two analogues of tetrahydrodicranenone B as well as a formal synthesis of tetrahydrodicranenone B () itself has been devised. The approach is based on an addition/elimination sequence of in situ prepared organocuprates to the iodocyclopentenone (). The procedure is compatible with functionalised substituents.