Extended Data Fig. 8: Calculated transition states of the Diels-Alder reaction between dienophile 2 and dienes 4 or 10.
From: FAD-dependent enzyme-catalysed intermolecular [4+2] cycloaddition in natural product biosynthesis
a, This data shows the calculated Diels-Alder transition states of Diels-Alder reaction between 2 and 4 leading to the four possible product regio- and stereoisomers. The computed barriers (all with respect to isolated reactants) show that TS-1 is the favored TS, suggesting that the reaction displays intrinsic regio- and stereoselectivity for the experimentally observed product isomer under enzyme catalysis. b, The DFT calculation supports an endo transition state and a concerted but asynchronous mechanism of the Diels-Alder reaction between 2 and 10. C–H hydrogen atoms are omitted for clarity. Interatomic distances are in Å. Energies are in kcal/mol.
