Recent advances in natural product synthesis by using intramolecular Diels-Alder reactions

A summary on a number of recently completed total syntheses of natural products achieved by using intramolecular Diels-Alder (IMDA) reactions as the key steps in the construction of their basic frameworks is reviewed. Focus of this review goes on the total synthesis of biologically intriguing and pharmacologically important natural products completed during the past 10 years and the completed total synthesis for each natural product. Also discussed are transannular Diels-Alder approaches and reactions using furan and other heterocyclic substructures and some prominent total syntheses achieved based on intramolecular hetero-Diels-Alder reactions. The IMDA reaction-based natural product synthesis are each divided according to the generally accepted structural classification of natural products. Furthermore, a brief summary of the stereo-chemical outcome of each mentioned IMDA reaction and the reported IMDA reaction step for each cited natural product synthesis are included in this review.