Recent applications of intramolecular Diels-Alder reaction in total synthesis of natural products

Diels-Alder (D-A) reaction is undoubtedly the most powerful [4 + 2] cycloaddition reaction in organic synthesis. It has been always considered as a model and a symbol of cycloaddition reactions. Intramolecular D-A reactions (IMDA) are also well recognized and can be employed in one or more steps for the total synthesis of several natural products. In this report, we wish to highlight the recent applications of IMDA as a key step in the total synthesis of biologically active natural products, including alkaloids and terpenes.