Diels-Alder Reactions in Creating Complexity in Higher Order Isoprenoids: Proposed Biosynthesis and Biomimetic Total Syntheses

Diels-Alder reactions and hetero Diels-Alder reactions play crucial role in building complexity in many naturally occurring isoprenoids. A number of structurally intriguing complex isoprenoids have been isolated form Nature, those are believed to follow a [4+2]-cycloaddition reaction in their biosynthetic proposal. In this focus review, we discuss on the recent efforts on biomimetic total syntheses of complex isoprenoids utilizing Diels-Alder and hetero Diels-Alder reactions. In particular, we have considered isoprenoids arising from a basic icetaxane, abietane, dinor-abietane, and abeo-abietane structural scaffolds.