Enantioselective Synthesis of Iridal, the Parent Molecule of the Iridal Triterpenoid Class

The monocyclic triterpene iridal 1 (parent molecule) is synthesized by an approach that allows access for several representatives of the iridal family as well as diversely substituted analogues. The success of the proposed synthetic plan depends upon the effortless stereoselective establishment of the trans C10/C11 dimethyl relationship in B-ring moiety 7 using a domino-based methodology and the higly efficient Miyaura−Suzuki type sp3−sp2 segment coupling 7 and 8, respectively.