The Diels-Alder cycloaddition is one of the most utilized reactions for the construction
of cyclic systems with high regio-, chemo- and stereoselectivity. Accordingly, this
versatile reaction has been broadly exploited in synthetic organic chemistry for the transformation
of natural products, structurally diverse molecules of biological interests, pharmaceuticals,
polymers and new materials. Nature has also used this cycloaddition reaction and Diels
Alderase enzymes were proposed in many biosynthetic pathways of secondary metabolites.
The aim of this account is to furnish to the scientific community an overview of reactions
using a Diels Alderase for natural product biosynthesis. The proposed biosynthetic
pathways involving Diels-Alder reaction are also summarized.